TANK GUN ACCURACY AT SHORT/MED RANGE

[rexford]

We have been computing shot accuracies based on typical range estimation errors (25% error) and projectile dispersion around aim point, and the results seem technically correct.

However,

Panthers and PzKpfw IVH's have about 100% hit probability against a fully exposed medium tank inside 500 meter range, which doesn't seem realistic.

What has been your experience with medium and short range accuracy in CM, and should a cap be placed on maximum weapon accuracy to model nervous nellies, dust or glare in the eye or a gunner who sneezes at a critical point? What would the cap on max accuracy be?

Should all shots hit at 200 meters? At 100 meters? At 500 meters? Never have 100% accuracy?


Our calculations seem to be missing something.

Thanks.

[Mark IV]

I have certainly had tanks, including those you mention, miss at ranges well under 500m and even under 100m. I had a Mk IV miss a Sherman under 200m in a tcp/ip game last week, and the M4 was broadside.

[aka_tom_w]

I was begin to wonder if I was the ONLY one concerned about this..

Here are the results of an earlier post regarding this issue:

from the readme or b24:

"- Gunnery accuracy equations modified slightly to permit greater accuracy at point-blank ranges."

I have played b24 as much as possible since it's release. I have enjoyed it VERY much.
It is stable and it is fun.

Does anyone here know what Charles means when he says "at point-blank ranges"?

I have now played a good many tank battles where the average range was 500 meters or less, and I would say, in my experience, there is a greater chance to hit modeled now for tank gunners. I like it, and I think it is noticable, reg, vet, Crack, and Elite tank crews now hardily EVER miss even their first shot at against NON hull down targets at less than 500 meters.

Has any one else noticed this increased accruacy? Getting the first shot off quick now REALLY counts for something. AND with the additional use of the Allied Tungsten hyper shot, tank battles at less then 500 meters, seem ALOT deadly than before!

I have no actual experience of whether or not this is now MORE realistic or less realistic, but in my own (limited) personal opinion, this NEW short range accuracy tweak, makes the game, and targeting aquisition, behave ALOT more like the accuracy charts of weapons tested at gunnery ranges, that have been mentioned in those two (very lengthy) Long range gunnery accuracy threads.

I sort of like the way the tank gunnery accuracy "feels" now. But may now be unrealistically accurate?
It does however make you even MORE careful with your tanks because you can't count on the likely hood of your oppenent firing a first shot miss that way it used to be. Getting that first shot off quickly seems ALOT more urgent now, making Vet Crack and Elite tanks crews EVEN more valuable!

Thanks again!


-tom w

(NOTE)

You'll notice I did NOT once use the phrase "superior gunnery optics" in the above comment.
(edited here from previous original complimentary post)

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aka_tom_w
Member posted 12-27-2000 03:28 PM
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Steve Replies:
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Big Time Software
Moderator posted 12-27-2000 04:35 PM *** **** ** **
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Tom, I think the tweak was only for VERY close range shots. Far closer than 500m. Something like less than 100m is my guess. Charles is out of town for a couple more days so I can't say for sure.

Steve

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aka_tom_w
Member posted 12-27-2000 05:53 PM *** **** ** **
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Hi Steve,

Thanks for the prompt reply.

I may have been mistaken or all the tanks firing were just getting lucky, but in the 300 to 500 meter range ALL tanks seem to be getting alot more hits than they used to, lately. I notice that no one is posting to complain about how often their tanks are firing and missing several shots in a row.

Maybe we have all just been getting lucky hits lately?

Thanks again

-tom w

[This message has been edited by aka_tom_w (edited 12-27-2000).]

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aka_tom_w
Member posted 12-29-2000 07:26 PM *** **** ** **


Remember the days of playing Chance Encounter with 3 Stugs vs 5 Sherms and you could not BUY a hit, as the tanks would miss two and three times in a row?

Anyone remember those days?

Well they are GONE now, for better or worse there are now ALOT more first shot hits at ranges less then 500 meters.
Try it and see. Tanks now RARELY if EVER miss at ranges less than 500 meters, I woud say the game is now MUCH more leathal in this respect than it ever was.

-tom w

[aka_tom_w]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Mark IV:
I have certainly had tanks, including those you mention, miss at ranges well under 500m and even under 100m. I had a Mk IV miss a Sherman under 200m in a tcp/ip game last week, and the M4 was broadside.<HR></BLOCKQUOTE>

Recently?

In b24?

If you can you should try Rune's Chance Encounter 2 And see how the tank gunnery accuracy has changed dramatically at ranges less than 500 meters since the b24 patch release.

-tom w

[Mark IV]

Wednesday the 27th in b24.

[aka_tom_w]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Mark IV:
Wednesday the 27th in b24.<HR></BLOCKQUOTE>

OK

We have found agreement on these kinds of issues in the past, so please don't consider this a confrontational opinion, perhaps just an inquiry, but don't you think, (if you think back to those Stugs and Sherms missing each other in the Chance Encounter Demo scenario) that ALL tanks now target and hit with ALOT more accuracy in b24? (on their FIRST shot)

I'm wondering (I could be wrong) if the accuarcy for all tanks at less than 500 m may now be unrealistically high?

OR Charles may fixed it and it is just right now?

But I would say Reg tank crews a ranges less than 500 m are hitting in the 90-95% range now on their FIRST shot.

So I suspect they never miss their second shot, and I suspect Vet Crack and Elite (especially) are now DEADLY accurate on their first shot. Maybe this is more real? I don't know, but I would suggest the tank gunnery accuracy at less than 500 m is noticably different in b24 than it was before.


Anyone else?

Comments?

-tom w

[aka_tom_w]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:

Should all shots hit at 200 meters? At 100 meters? At 500 meters? Never have 100% accuracy?

Our calculations seem to be missing something.

Thanks.<HR></BLOCKQUOTE>

I completely trust Steve and Charles when they tell us that there are NO calculations or chance to hit odds or chance to DO anything in CM that is set to 100% for anything. They have been very clear in the past that no algorythms or chance to hit calculations ever equal a 100% result.

MarkIV points out that tanks still miss, I played two TCP/IP tank battles yesterday for about a total of 9 to 10 playing hours, and I did see the odd miss against fully exposed targets less then 500 meters, so I know the chance to hit is not 100% but the first shot chance to hit is IMHO now alot higher, but it is not 100%


-tom w

[aka_tom_w]

Hi

Count the dead Sherms http://www.battlefront.com/discuss/smile.gif

All killed at ranges less than 550 m most with first shot hits by two Reg hull Down Panthers.

How many are there?

http://142.55.231.199/aka_tom/ac.jpg

[This message has been edited by aka_tom_w (edited 12-30-2000).]

[This message has been edited by aka_tom_w (edited 12-30-2000).]

[JoePrivate]

<BLOCKQUOTE>quote:</font><HR>tom_w wrote:

Remember the days of playing Chance Encounter with 3 Stugs vs 5 Sherms and you could not BUY a hit, as the tanks would miss two and three times in a row?

Anyone remember those days?<HR></BLOCKQUOTE>


I also played CE a lot but can only remember a couple instances where a Sherman-Stug duel lasted more than one or two shots. Usually it was over bang bang.

I hadn't noticed a higher instance of first shot hits with beta24 however I will keep an eye out for it. It would be easy to setup a quick gunnery test and compare the results with 1.05, then you would know if you were on to something.

[PzKpfw 1]

No Tom see what happened was Charles & Steve got so sick of hearing us go on about LR gunnerey models that they decided to get revenge on us by doing the oposite http://www.battlefront.com/discuss/biggrin.gif.....


Regards, John Waters

------------------
"We've got the finest tanks in the world. We just love to see the
German Royal Tiger come up on the field".

Lt.Gen. George S. Patton, Jr. February 1945.

[aka_tom_w]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:
No Tom see what happened was Charles & Steve got so sick of hearing us go on about LR gunnerey models that they decided to get revenge on us by doing the oposite http://www.battlefront.com/discuss/biggrin.gif.....


Regards, John Waters
<HR></BLOCKQUOTE>


Hi John http://www.battlefront.com/discuss/smile.gif


Yes, I can see that.

I have not tested long range accuracy in b24, but at ranges less than 500 m, it seems ALL tanks are now REALLY accurate. It is VERY noticable in my opinion. I'm surprised more people have not commented on it. My experience playing here with Reg crews show they can now hit most non hull down targets, up to 90% of the time with their first shot. I think that may be a tad generous for Reg crews. But I could easily see those kind of Odds or better for Elite tanks crews.

We'll see what Charles has to say when he returns.

-tom w

[Jarmo]

I have certainly had my share of close range misses in b24.
With all kinds of tanks.

[retarded_keydet]

I was recently playing a tcp/ip game with my brother and was a little surprised at what seemed like more accurate tank gunnery. I had a veteran stug hidden in a turret down position just behind the crest of the hill. After I spotted his sherman I simply popped up and knocked him out in one shot. I don't think his tank even had enough time to turn towards me and try to engage.

------------------
There was a long silence of rememberance for the dead, to which I added these names:
Ernst Neubach, Lensen, Wiener, Wesreidau, Prinz, Solma, Hoth, Olensheim, Sperlovski, Smellens, Dunde, Kellerman, Freivitch, Ballers, Frosch, Woortenbeck, Siemenlies...
I refuse to add Paula to that list, and I shall never forget the names of Hals, or Lindberg, or Pferham, or Wollers. Their memory lves within me.
There is another man, whom I must forget. He was called Guy Sajer.

[Colin]

Where do I find CE 2?

Or email it my way if you're feeling nice!

------------------
And if we abandon any platform, I can assure you it will not be the Macintosh.

-Steve

My website! (http://cm4mac.tripod.com)
A major source of Wild Bill scenarios!

[JoePrivate]

Colin,

A pack of Rune's scenarios just uploaded today, including CE2, can be found at:

http://WWW.COMBATMISSIONS.CO.UK/

[rexford]

We recomputed hit probabilities vs. Sherman front after reading earlier responses:

PzKpfw IVH/StuG IIIG 75mmL48 APCBC

95% at 300m
93% at 400m
90% at 450m
76% at 500m

Panther 75mmL70 APCBC

95% at 400m
93% at 500m
81% at 600m

The guns are very different in two respects, Panther 75 has flatter trajectory due to higher speed, so less aim error per range estimate erro. Panther 75 also has considerably less shot-to-shot dispersion for a constant aim.

The computed Panther and PzKpfw IV accuracies vs. range are typical by falling suddenly at a given range.

Inside 450m or so, PzKpfw IV 75mm should not be significantly less effective than Panther in terms of hit probability, which suggests that alot of PzKpfw IV's in defensive position may be more effective than fewer Panthers if panzers are vulnerable to flanking. PzKpfw IVH may also have higher rate of fire if heavier and longer Panther rounds slowed fire rate

Does anyone know if Panther rate of fire was less than PzKpfw IVH? A U.S report estimates 7-8 rounds per minute for Panther, which seems high but Tigers could pump out steel at close to that, at least initially when rounds were easy to grab.

75mmL48 at 450m should consistently kill Sherman front armor even with a 25° angle between hull and firer. 65° angle hits on 38mm Sherman side armor would also go right through, and about half the hull hits at 25° hull angle to PzKpfw IV hit side hull
armor.

If firefight is less than 500m, PzKpfw IVH may be as lethal as Panther if panzers get first shot.

Barkmann's Corner is an Advanced Squad Leader scenario where Barkmann did foot recon to spot oncoming Shermans, ran back to his Panther and then sped out of the woods and fired on Shermans, one after the other, at really close range (Shermans tried to back-out of Panther view but couldn't). If memory serves right, Barkmann got them all, and kept pumping in shots until they burned.

Would Barkmann have done this in a PzKpfw IVH that might crash and burn after one Sherman hit? Probably not, so PzKpfw IVH may not always be the best bet and Panther could be superior.

There is another story where a Panther in Normandy was being shot at and hit by a Sherman at close range, and the shots kept hitting about the same spot on the glacis and bouncing off. The Panther commander noticed another Sherman trying to flank his tank so the Panther rotated its turret and took out the threatening Sherman while the first Sherman kept bouncing shots off the panzer glacis. Panther commander figured correctly that Sherman was fixated on getting hits and wasn't about to change a thing.

American tankers taught to aim at mid-point on vertical tank profile, which is glacis, and at close range shots will bunch about aim point. Some Sherman tanks obviously kept to their teaching exactly as taught even when continued hits in same spot did nothing.

Germans aimed at turret/hull meeting point, which meant that half hits struck vulnerable turret, half hull, and aim point hits might disable turret by jamming turret ring or penetrating weak armor.

Regarding range estimation errors, Tiger commanders expected to estimate range within 10%, on average, while others tried for 25%, based on German training manuals like Tiger Fibel.

[Mark IV]

I just tried an unscientific little test, with an all-armor QB on a small map, heavy woods.

Allies, attacking:
4) M476W
4) M4E8
1) M4(105)

Axis:
2) Panther G
2) Mk IVH
2) Mk IVG
1) StuGIII

All crews were Regular. Longest shot fired was about 253m. Almost all were under 200m, bulk between 189 and 153m.

Out of approximately 34 shots fired, there were at least 18 clean misses.

There were 14 kills. 8 Allied, 6 Axis vehicles destroyed.

There were at least 3 non-lethal hits (ricochet off a Panther, a track hit, and a gun hit).

1 Allied, 2 Axis survived at the time of the AI auto-surrender. The German defense was relatively static (the Panthers never moved at all). The Allied AI unwisely tried to force a gap in the trees, 2 or 3 at a time, though it was nice for test purposes.

The Panthers were closest to the action, and fired 5 shots with 3 kills and 2 misses, before succumbing.

The MkIVHs fired the most, and one of them was the kill leader with 3 AFVs.

The Allied kill leaders were an M476W and one of the easy-eights. The E8 had the longest range kill at 241m (with 3 misses from that range).

[rexford]

At 500m, Sherman vertical height will appear to be 0.053" high to the naked eye. With a 2.4x magnifying gunsight like PzKpfw IVH used, the Sherman profile looks like it is 0.126" high.

To maximize accuracy, gunners need to aim close to the vertical center, which is 0.063" above the bottom. That's 1/16 of an inch!!

Nervous gunners, bad light, dust or other factors might lead gunners to get off shots at a point removed from the vertical center, which increases number of shots that miss.

Later Panther A and all Panther G gunsights had 2.5x/5.0x gunsight magnification, which could double target height observed by gunner and would aid in getting the best accuracy possible. At long range, Panther has smaller dispersion than PzKpfw IV, flatter trajectory and less aim error and better gunsight.

At 2500m, Sherman vertical height looks like 1/40 of an inch to PzKpfw IVH gunner. Imagine the difficulty in aiming at the center of something that appears to 1/40 of an inch high, especially if you are thinking that your vehicle may be hit soon by an M36 or aircraft and your hand is shaking slightly and sweat is pouring down your face in a closed down tank in the August sun and powder smoke is in your nostrils and lungs!

A Panther D is reported to have hit and knocked out a T34 at over 2500m during the Kursk battle, before the Panther self-destructed.

Later JagdPanthers had 10x magnification gunsights! Tiger II may have had 3x/6x. Nashorn had 5x.

While Sherman at 2500m looks like it is 1/40 of an inch high to PzKpfw IVH gunner, it looks like 1/10 of an inch high to aiming member of JagdPanther crew.

To get maximum accuracy one needs the proper gunsight.

Early Shermans used in desert reportedly used gunsight on top of tank instead of coincident with barrel, and connection between gun barrel elevation and gunsight was prone to alignment errors. Early Shermans supposed to be inaccurate due to gunsight alignment problems, as well as poor optics if various sources are to be believed when they say that pre-war world depended on German optical glass, and once war started Allies had to struggle to make decent gunsights.

[Mark IV]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:
American tankers taught to aim at mid-point on vertical tank profile, which is glacis, and at close range shots will bunch about aim point. Some Sherman tanks obviously kept to their teaching exactly as taught even when continued hits in same spot did nothing.

Germans aimed at turret/hull meeting point, which meant that half hits struck vulnerable turret, half hull, and aim point hits might disable turret by jamming turret ring or penetrating weak armor.<HR></BLOCKQUOTE>

The US doctrine may have evolved. In the July '44 manual, it says:

The proper range line is laid on the center of mass of the visible portion of the target. At very short ranges the point of aim may be shifted to the most vulnerable spot visible; for example, a gun port in a concrete pillbox, the turret ring, or a lightly armored point on a tank.

This FM (17-12 Tank Gunnery 10 Jul 44) is the most fascinating reading... one of these days I'll have to post what it says about HE skip fire... great diagrams.

[rexford]

In MARK IV's message, were the misses due to targets obscured by woods or were they out in the open.


Trying to hit something in the woods where the aiming point may be the center of observed smoke may be alot different from something sitting in the open.

Details would be appreciated.

Thanks.

[rexford]

Despite Allied combat against Tiger and Panther in Italy, and Soviet notes on their experience, Allied tankers in France seem to have acted as if they were the first to combat the heavy German armor. M10 gunners aimed at the Panther glacis instead of the vulnerable center mantlet area.

[Mark IV]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:
In MARK IV's message, were the misses due to targets obscured by woods or were they out in the open.<HR></BLOCKQUOTE>

Some were partially obscured. Some were in the open. No allowance for hull down.

So I tried again with 8 PzIVH vs. 8 M4E8, Open, Flat, Farmland, Clear... a regular OK Corral.

30 total shots, 13 misses. All under 415m, most between 369 and 269m. Axis took 14 shots, 8 hits, 6 misses.

Allies took 16 shots, 9 hits, 7 misses.

[rexford]

The open field hit percentages in mark IV's message seem low, which is the other extreme. At ranges under 500m with the U.S. 76mm, it takes really bad range estimation to miss or an out of alignment gun. Like estimating the target at 340m is at 600m.

Were the misses high/low or wide?

[rexford]

Regarding Mark IV's last message on open field hit probability, there are stories where green troops in Jagd Panthers missed shots at 400m by aiming very low. It might be helpful if you could play the scenario again and see how the results compare and also keep an eye out for the type of misses.

Previous messages complained about alot of easy hits at 400m on first shots, the open field experiment Mark IV completed goes the other way.

[aka_tom_w]

OK

I admit I have not had time or found time to conduct some gunnery range tests with b24.

I admit that my subjective opinion of (maybe) too many first shots hits could be, in error.

I think that gunnery accuracy has changed. Perhaps it is MORE realistic now.
Having looked at the results of MarkIV's tests, I must re-evaluate my opinion on this. MarkIV's tests look like there are still plenty of misses and I think that is a good thing.

Rexford,

We welcome your opinions and contribution to this discusion, and if I may, since you may not be aware of the history regarding this issue, I would like to suggest that you take some time (I mean this to help you with the background here) and read through these threads. Post's by John Waters and Steve and Charles are particularily relevant. There is a LONG history here of debate and discussion regarding gun acuracy and it has been VERY heated and detialed at times:

If anyone one else know's of any other relevant threads that I have not cited below can you please post the link to that thread if I missed an important one for Rexford (or any one else new to this discussion here) to read.

(this is a BIG one) http://www.battlefront.com/discuss/Forum1/HTML/009258.html

(This one Started it all I think) http://www.battlefront.com/discuss/Forum1/HTML/004572.html

(this one, below, is HUGE about optics and long range accuracy, 24 pages long!! and somewhat recent, just before your time, I would say this thread is a MUST read for you http://www.battlefront.com/discuss/smile.gif )

http://www.battlefront.com/discuss/Forum1/HTML/011342.html

more:
http://www.battlefront.com/discuss/Forum1/HTML/009348.html
http://www.battlefront.com/discuss/Forum1/HTML/008896.html


MarkIV, what conclusions do you draw from your test results? Do you feel there has been a noticable change in accuracy? do you think it is more realistic or less?


-tom w

[This message has been edited by aka_tom_w (edited 12-31-2000).]

[Mark IV]

I ran a couple more:

1500 pt. QB
Rural, Flat, Open
9 PzIVG vs. 9 Easy-8s, all VETS.
Ranges from 295 to 371m.

Axis: 9 shots, 4 misses.
Allies: 16 shots, 5 misses. 2 of the Allied misses were at German tanks reversing. 2 of the German misses were from the same reversing tanks.

1500 pt. QB
7 Easy-8s vs. 14 PzIVH, all VETS.
Farmland, open, flat.
Ranges from 336 to 411m.

Allies: 12 shots, 5 misses. 3 of the missed targets were either in wheatfields or with wheat intervening.
Axis: Bunch of shots, several misses observed. Basically I quit counting at this point.

I would conclude that there is no such thing as a 100% hit chance. Some misses were stationary vehicles with Vet crews firing at stationary targets over flat, clear terrain in the 300m range. Sh*t happens, especially on battlefields.

By the 2nd shot (for those lucky enough to have gotten that far) some units were buttoned or had commmanders hit by the ranging MGs. That would be a factor. Some crews appear to just be more adept than others- that's realistic. There seems to be a higher chance of hitting on the 2nd shot, but the little tests weren't designed to prove that.

One observation is that PzIVs burn and explode a helluva lot more than the HVSS Shermans. Nice.

As for feeling right, I haven't been in any real tank battles, but I have missed deer at giveaway ranges for no other reason than operator headspace, and they weren't shooting back. It "feels" right to me, with the above qualification.

[Jeff Duquette]

Just a suggestion on this rather fascinating topic. Download the DEMO or order the full blown version of "Steel Beasts".
http://www.shrapnelgames.com/SBDemo.htm

SB is probably one of the most realistic games (IMHO) out there for getting a feel for actual tank gunnery. Try some of the training range exercises and turn off your stabilization and don't use LRF's. By doing this it should give you a since of what WWII tank gunners were up against. It reinforces the importance of magnification in main gun optics, and target range estimation.

Question to Armour Grogs: I've been searching around for German WWII fire commands and there sequence. Can anyone provide suggested references?

[Mark IV]

I will add that I did not run such a test in 1.05, so I cannot make an informed comparison (maybe when I get back from the NY trip).

Overall I've been delighted with the 1.1b24 patch.

As for tank battles, I did get to see several large mock battles at Hoehenfels and Grafenwoehr during ARTEPS in Germany, from an evaluator's-jeep-driver and RTO perspective.

My chief impression was one of mass confusion, with big things moving fast in poor visibility. There was a lot of dust, smoke, and tear gas involved, with flash-bangs from the Hoffman devices used to simulate gunnery. I cannot imagine scoring with every pull of the trigger in those conditions.

Of course, they were simulating a Soviet-style echelon attack against US overwatch tactics. My experiments were with stationary lines of tanks.

Still, CM seems to have it about right!

[Michael emrys]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:
It reinforces the importance of...target range estimation.<HR></BLOCKQUOTE>

I think this is an important point. During most of WW II tank rounds did not travel at anything like the velocities of present-day APDSFS shot. Thus their trajectories had a higher arc and range finding was more crucial. Usually range finding was accomplished via the TC's estimate based on eyeballing it through a pair of binoculars. Obviously experience, lighting, obscuration counted for a lot here. Usually the first round missed at anything over 500 meters and the TC had to talk the gunner onto the target. Then, once the gunner was on the target, there could be the matter of finding a soft spot in the opponent's armor before a kill could be registered. This was particularly a problem for the Allies.

This is no doubt frustrating for players whose experience is with modern (especially laser equipped) armor where first round hits (and kills) beyond 2,000 meters are common. But then, war is hell, ain't it?

Michael

[TheDesertFox]

<BLOCKQUOTE>quote:</font><HR>Question to Armour Grogs: I've been searching around for German WWII fire commands and there sequence. Can anyone provide suggested references?<HR></BLOCKQUOTE>

Have a look at Wolfgang Schneider´s "Panzertaktik" or see if you can get hold of a copy of Kaufmann "Panzerkampfwagenbuch".

Or you can try to get a 1950s copy of the Bundeswehrvorschrift "Der Panzerzug" and "Die Panzerkompanie" which included basically all lessons learned during WW2 and was written by former officers of the Wehrmacht.

Try Bundesarchiv Freiburg.

Cheers

Helge

------------------
Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!
- The DesertFox -
Email: TheDesertFox@gmx.net
WWW: http://www.geocities.com/desertfox1891

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Mike Said:

During most of WW II tank rounds did not travel at anything like the velocities of present-day APDSFS shot. Thus their trajectories had a higher arc and range finding was more crucial.<HR></BLOCKQUOTE>

yup

In theory 88mmL56 and L71 as well as the 75mmL70 had relatively flat trajectory AP shot (this is perhaps also true of the 17-pdr, US 90mm, and 3inch guns). If you take the "Tigerfibel" to heart, it wasn't as critical to establish perfect range for targets at ranges of 1000 meters or less (assuming a typical tank sized target) due to the fairly flat trajectory of the 88mmL56 armour piercing rounds. Line Of Sight is approximately equal to flight path of round at ranges of less than 1,000 meters.

This is in keeping with modern battlesight engagement philosophy in which range is pre-indexed in the tanks range finder (as I recall the old 105mm had maximum battle sight settings for SABOT of something like 1000 meters and HEAT was like 800 meters). Battlesight gunnery relies on the relatively flat trajectory of armoured piercing ammunition to ensure respectable first round hit probability.

Desert Fox:

Thanks for the suggestions. I am still waiting on the translated version of: "Panzertaktik - German Small-Unit Armor Tactics" by Wolfgang Schneider, Frederick Steinhardt (Translator). Ordered it from AMAZON several weeks ago. I think the English Version will be released in APRIL. I am hoping it is not so much of a picture book ala Wolfgang Schneider's "Tiger's in Combat II". Great book, but I was disappointed in the over abundance of photo's and under-abundance of text. "Tigers in Combat II" kind of reminded me of: "Tiger I on the Eastern Front" by Jean Restayn (a great deal of photo - overlap between the two books). I was really hoping for something more akin to Jentz's "Tiger I & II: Combat Tactics".


[This message has been edited by Jeff Duquette (edited 12-31-2000).]

[rexford]

Thanks for the past message threads which we started to read through and are about 10% through. We would like to add some notes regarding computer models for tank fire that include range estimation and dispersion.

We have German dispersion stats and hit probability tables based on perfect range estimation, and built a simple to use computer spreadsheet around that data, which we use to predict hit percentages for first and follow-up shots. The spreadsheet also predicts slope effect based on T/D and ammo type, armor quality modifiers, penetration at range, fall of shot angle, predicts whether round penetrates since % is often between 0% and 100%), and if shatter gap is a possibility.

The computer spreadsheet uses an average range estimation error of 10% (ace), 25% (average or 35% (poor), and randomly picks a range estimation error for each shot from a statistical curve for crew rating.

At 2000m against a 2m high x 2.5m wide target, an average Tiger I crew will obtain first shot hits on about 5% of the shots. The hit probability given on the German dispersion tables are for perfect range estimation and give hit % for one times and (in brackets) two times the dispersion.

The hit % in the German tables for two times the listed dispersion (doppelt 50% ige streung) does not include range estimation errors but is related to errors made in picking the proper aim point, gun misalignment, etc (a friend speaks and reads German and translated for us).

With perfect range estimation and double gun dispersion, 88L56 will hit 2m high x 2.5m wide target 50% of time on our copy of German data. With 25% average range estimation error and bell shaped distribution of errors about average, first shot % falls to about 5% (4 hits in 88 tries using our spreadsheet).

If Tiger crew can estimate range to within 10% average, hit % rises to 15% on first shot at 2000m. If CM uses 21%, it seems closer to Tiger Vet-Elite status and takes note that Sherman may be larger target than 2m x 2.5m.

We realize that adding to old message strings is not always productive or appreciated, and we will try to avoid it. The above explanation seemed appropriate after reading some of the string you kindly brought to our attention.

[rexford]

Regarding previous e-mail from this writer, it should also be noted that the German estimate of 50% hits for first shot by 88L56 on 2m x 2.5m target at 2000m does not appear to be based on field trials, but appears to be calculated. We did the math, and using twice the listed dispersion reproduces the bracket hit % and represents 0m range estimation error.

Many of the calculations and pronouncements in German and other country documents from WW II appear to be based on field tests but are more likely to be calculations from office data. Penetration ranges are often from this type of source.

[aka_tom_w]

Hi Rexford

Keep reading those old accuracy threads and I hope you will keep posting here. New comments and insight into tank gunnery accuracy are always welcome. http://www.battlefront.com/discuss/smile.gif

Its probably about time to start ANOTHER reallly long tank gunnery accuracy thread http://www.battlefront.com/discuss/smile.gif

I sort of miss the old dead ones I used to participate in.

The fact that Charles has made ANY changes at all to the chance to hit percentages in his algorythms really represents a substantial break through here, as he has been VERY reluctant in the past to change anything with respect to accuarcy and "chance to hit" probabilities in his equations.

I do hope you will read all the responses from Steve and Charles in those previous threads I posted. I suspect that some time before Tuesday morning we will read something from Steve here. Please bear in mind Steve and Charles consider their calculations and algorythms to determine hits and penetration results in this game to be a trade secret. No actual numbers, formulas, calculations, or algorythms have ever been publically released about exactly how tank gunnery really works in his calculations.
I respect their decision in this matter.

So instead we all do little tank gunnery range "experiments" to try to get to the bottom of what's really in those equations and algorythms. Its somewhat of an elusive quest to get to the heart of how tank gunnery is coded in this game by observing the results of gunnery range tests, and recording those results and sharing them here with others who are equally curious, there are only a handful of us http://www.battlefront.com/discuss/smile.gif.

It is my opinion that there has been a slight modification of some of the chance to hit percentages for some tanks in b24 as it is my opinion that tank gunnery at ranges less than 500m is now more accurate then it was before the release of b24.

This is the first time in 5 patches and two public beta updates there was ever ANY mention of altering or updating ANY gunnery accuracy or chance to hit percentages or data.

It is my conclusion that the game is now MORE fun because of this. I wish I could comment and say it is now more realistic, but I really have no experience or knowledge to make such a statement or claim. But I can say with confidence that more tanks brewing up quicker as a result of more first shot hits is MORE FUN! http://www.battlefront.com/discuss/smile.gif

-tom w

[This message has been edited by aka_tom_w (edited 12-31-2000).]

[This message has been edited by aka_tom_w (edited 01-01-2001).]

[rexford]

If one compares German 88L56 and American 76mmL52 APCBC hit chances while assigning each the same dispersion, which is more accurate?

German 88 loses velocity slower than 76mm round so has a flatter trajectory and will have a higher hit probability. We compared German velocity-vs-range data for 88L56 and American data for U.S. 76mm, and Tiger I round will outshoot 76mm at medium and long range with same dispersion.

76mm starts out at 2600 fps, 88L56 at 2558 fps, but 88 catches up and passes after a while.

Our spreadsheet considers estimated velocity-vs-range data for each projectile and computes trajectory height over the target aim point, using double dispersion for initial shot.

On a related though different topic, 17 pdr APDS appears to lose stability, accuracy and penetration on close to 50% of the shots, based on analysis of many field tests, due to a piece of sabot hanging on longer than the others which unbalances ammo. In U.S. tests at Isigny, 17 pdr accuracy was terrible, and penetration suffered.

Will CM give 6 and 17 pdr APDS variable dispersion, where accuracy and penetration may drastically change from tank to tank, or battle to battle?

U.S. gunners at Isigny said that 76mm HVAP was most accurate round they had ever fired. British explained that APDS rounds had not been adequately proofed and an earlier test had resulted in clean penetrations of Panther glacis at around 700m or so (lost reference and are using my notes). APDS shots at lesser ranges at Isigny bounced alot.

When we analyzed 76mm HVAP with our spreadsheet it did lose velocity faster than 88mm or 76mm APCBC, but it was still more accurate at useful ranges due to large velocity difference.

When Soviet T62 fired state-of-the-art APFSDS during 1973 war (APDS with fins that came out of round after it left smooth barrel, which allowed really high velocity), Israeli's reported that T62 shots would occasionally hit the ground at wild angles. New discarding sabot ammo types seem to suffer from teething problems.

Our spreadsheet also bases lateral hit probability on motion across line of sight, so targets moving straight at a gun do not lower the hit probability due to motion status.

Changes in lateral and vertical hit probability occur because gunner uses incorrect lead or need to estimate lead reduces commander's ability to estimate range (too many irons in the fire at one time). No lead involved when target moves directly at gun.

From what you've said in past messages it looks like CM uses a similar system.

Just out of curiousity, does 75mm Sherman fire faster and more often than Panther in CM, based on your experiences? Power traverse gets gun on target quick.

[aka_tom_w]

Hi Rexford

I hope you don't mind if I ask, I and hope you will excuse my ignorance if I should know this already, but who are "we"?

Are you speaking for a group of designers for another WWII tank gunnery Sim game?

Are you familiar with how tank gunnery is simulated in Panzer Elite?

What is the purpose of your data, research stats and spreadsheets if not for gaming purposes? Would you share your data with Steve and Charles? Is it in the public domain? Do you give it away or sell it? Just curious.

Are you affiliated with a 2D board gaming interest? Miniatures perhaps?

Your comments and observations and posts seem VERY well informed and I look forward to your further observations.

Thanks

-tom w

[This message has been edited by aka_tom_w (edited 01-01-2001).]

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Rexford Said:
Does anyone know if Panther rate of fire was less than PzKpfw IVH? A U.S report estimates 7-8 rounds per minute for Panther, which seems high but Tigers could pump out steel at close to that, at least initially when rounds were easy to grab.<HR></BLOCKQUOTE>

Someone quoted a French Study ('Le Panther 1947') conducted following the war in which an astounding 20 rounds/minute test range ROF was indicated. Look at:
http://www.battlefront.com/discuss/Forum1/HTML/013902.html

As the details regarding the purpose of this test were not included in the original posting, and I don’t have access to a copy of 'Le Panther 1947' myself, I cant comment on the context.

However 20 rounds per minute does not seem realistically possible when engaging point targets such as tanks (or any targets with accuracy for that matter). I would be more inclined to look at CAT scores as a starting point or bench mark for average time of engagements, none of which come even close to a 1round/3sec ROF (this in spite of modern advantages of stabilization, LRF’s, and ballistic computers).

<BLOCKQUOTE>quote:</font><HR>Rexford Said:
Many of the calculations and pronouncements in German and other country documents from WW II appear to be based on field tests but are more likely to be calculations from office data. Penetration ranges are often from this type of source.<HR></BLOCKQUOTE>

I have heard this stated before regarding WWII penetration data by Benjamin Etxaburu on TankNet. No doubt what we are seeing in typical accuracy tables such as those presented in various works by Jentz or AORS4 represent best fit curves for field test data. Actual test data, if plotted, would be spread about central points with respect to range. Plots of accuracy with range for various WWII high velocity weapons typically resemble relatively smooth bell shaped curves (Increasing range along the horizontal axis...probability of hit on the vertical).

There is nothing inherently wrong with establishing a best fit relationship for field test data. For example: A common civil engineering problem might be strength of concrete relative to: time of curing, and mix design. Hundreds of compressive strength tests might be conducted and subsequently plotted and reduced to a simplified best-fit curve...a compressive strength vs. time curve. The casual observer might look at these smooth curves and come to the conclusion that it is “too perfect” and not based on real data.

<BLOCKQUOTE>quote:</font><HR>German 88 loses velocity slower than 76mm round so has a flatter trajectory and will have a higher hit probability. We compared German velocity-vs-range data for 88L56 and American data for U.S. 76mm, and Tiger I round will outshoot 76mm at medium and long range with same dispersion.
76mm starts out at 2600 fps, 88L56 at 2558 fps, but 88 catches up and passes after a while.<HR></BLOCKQUOTE>

Do you actually have access to test data detailing velocity degradation relative to range for WWII armoured piercing munitions, or are you estimating this? I have seen only one set of data for the Panthers 75mmL70. I would love to take a gander at additional test data. Any suggested ref’s?

One Interesting Note on maingun accuracy:

Training exercises involving tank gunnery have not changed much with respect to ranges of engagement since WWII. Present US ARMY training for table VIII max’s out at about 2000-2100 meters. Jentz indicates that Tiger and Panther crews typically trained on stationary targets placed at ranges of 1200 to 2000 meters. The WWII US ARMY FM17-12 indicates test ranges targets were to be placed between 300 to 3000 meters.

Rexford: One thing I have been curious about…you consistently speak in terms of plural folks. “We did such and such” and “Our testing showed this”. Maybe I missed this in a previous post, but are you speaking for a group?…or are you a member of the Borg? I dont wish to be assimilated http://www.battlefront.com/discuss/wink.gif

uupps...I see Tom has already beaten me to the punch on this question.


[This message has been edited by Jeff Duquette (edited 01-01-2001).]

[rexford]

We have velocity versus range data for most German guns, APCBC, HE and APCR, as well as American data in TM 9-1900.

88mmL56 APCBC velocity from 0m to 2000m changes from 780 m/s to 607 m/s. That's 2580 fps to 1991 fps, for a -23% drop in speed over 2000m.

76mmL52 APCBC goes from 2600 fps at 0m to 1910 fps with M1A1C gun and 1978 fps with M1A2 gun. Small differences, but 88L56 is slightly more accurate if one considers better gun sight and possibly smaller dispersion.

We don't have American dispersion data for their APCBC. We do have dispersion for 50mm L60 APC (very small, even smaller than 88L56),50mm APCR, and for 75mmL48 APCBC and APCR. 76.2L51.5 used by Germans has largest round to round dispersion we have ever seen for main ammo, 75L48 is not far behind.

U.S. velocity loss with range based on a commonly accepted method of estimating velocity with range called Sciacci's method, using ballistic coefficients. German data for striking velocity at range is probably based on similar estimates. It is very difficult to measure velocity accurately at 2000m.

British field test data for lead errors versus moving targets suggests that errors don't improve as number of shots increases. Leading a target is tricky stuff, you move the gun with the target as it moves and then move the gun out in front by the desired lead and quickly pull the trigger.

Following is a detailed discussion regarding potential problems with published data. We are constantly re-examining published info and our conclusions.
--------------------------------------------
Published Russian penetration data is defined in WW II German documents as DeMarre calculations against "zementen platten" using a penetration constant K, which suggests face-hardened plate. Russian data is similar to German for AP and APBC, main difference is ballistic cap on APBC slows velocity loss so penetration at range is greater.

Russian penetration data looks like test data but it probably is calculated, we have American test data for 122mm APBC versus U.S. plate at angles from 0° to 70° and it goes through alot more than 168mm at 0m and 0°, and it has unbelievably low slope effect due to flat nose. 122mm APBC slope multiplier of 1.62 versus Panther glacis at 55°, while U.S. 76mm APCBC has 2.52.

We have carefully reviewed alot of German, U.S. and British penetration range listings over a long period of time and most eventually prove to be calculations using available information. British charts even say, on occasion, that about 10% of penetration ranges in a document are based on actual field tests and rest are calculations, but report won't say which is which.

Panther and Tiger Fibel contain figures showing how far guns could penetrate enemy armor such as Matilda and T34, and it all appears to be calculated based on (incorrect) assumption that T34 and Sherman armor was same resistance as German penetration test plate.

The publishers of penetration ranges sometimes thought they represented field tests, and say they are test results based on a curve of best fit through field results, but ALOT of data out there was computed in an office and is not reliable.

Jentz presents alot of penetration range data and it appears to be based on field tests. Like when they shot all sorts of guns and ammo at PzKpfw IIIH front hull in Africa and reported the penetration ranges, this is the real thing (we have original reports, they match and also verify it is a test result).

The British often tested ammo at 30° and then used an assumed slope multiplier to convert data to 0°, which overlooked T/D ratio and presents questionable data for
0°. If 17 pounder APCBC penetrates 140mm/30° at a given range, 0° penetration might be listed at 140 x 1.25 = 175mm if 1.25 is assumed multiplier.

We have a published set of U.S. penetration data that is all based on one set of slope multipliers for all ammo and all armor thicknesses, so most of the data is suspect.

When Soviet data is presented for guns and ammo pen. range versus Tiger II in Jentz, we went through the calculations and the data seems to be real. However, Soviet pen. ranges are often based on calculations from their published data which assumes that AP and APBC penetrate same armor at same velocity, so both have same penetration at 0m: this is unlikely to be true, AP is sharp nose and APBC is flat nose (sounds like Land Before Time).

Changes in 122 flat nose penetration with velocity are also different from 122mm AP.

That German 50% hit probability by 88L56 against 2.5m x 2m target at 2000m is a calculation based on 0m range estimation error, we reproduced the analysis from original German data sheets.

Analysis suggests that 88L56 has 5% accuracy at 2000m vs. 2.5m x 2m when 25% average range estimation error is used with bell shaped distribution curve, based on trajectory and dispersion analysis.

British analysis of Panther A armor shows it to be face-hardened on lower front hull and hull side. We have original reports on this. How many books list Panther A hull side armor as face-hardened. Panther D glacis appears to have been face-hardened at first, even though it exceeded 60mm.

We play armor miniatures and have graphs that we use to resolve play. Plus the computer spreadsheet that computes everything one might want to know. We are thinking of putting the spreadsheet and supporting documentaion booklet into the public domain when we finish data collection in a month or so.

Our group is a loose collection of folks that look at things and present data and speculation. We then try to confirm the speculation.

My profession is civil engineering, licensed airport engineer in New York, and mathematical models are a hobby. Tank gunnery makes an excellent subject since it is loaded with odd twists and turns, like shatter gap.

Your game seems to be quit excellent and we enjoy the forum.

[Germanboy]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:
Germans aimed at turret/hull meeting point, which meant that half hits struck vulnerable turret, half hull, and aim point hits might disable turret by jamming turret ring or penetrating weak armor.<HR></BLOCKQUOTE>

Just to confirm this, I talked to a German vet from a Panzerjägerabteilung (drawn) yesterday, and the first thing he said when asked about the 37mm PAK (aka Heeresanklopfgerät) was that you could get a kill even with heavy tanks when aiming for this point, and that was what they were trained to do anyway.



------------------
Andreas
Der Kessel (http://www.geocities.com/greg_mudry/sturm.html)

Home of „Die Sturmgruppe“; Scenario Design Group for Combat Mission.

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Rex Said:

We have velocity versus range data for most German guns, APCBC, HE and APCR, as well as American data in TM 9-1900.<HR></BLOCKQUOTE>

Do you mean “TM 9-1900 Ammunition, General (3 July 1942)” or “TM 9-1907 Ballistic Data, Performance of Ammunition (23 September 1944)”?

<BLOCKQUOTE>quote:</font><HR>We are thinking of putting the spreadsheet and supporting documentation booklet into the public domain when we finish data collection in a month or so.<HR></BLOCKQUOTE>

I would be most curious to see your groups findings on WWII gunnery/accuracy. What is your bottom line impression of CM's accuracy model for tank fire? Or is your jury still out?

<BLOCKQUOTE>quote:</font><HR>My profession is civil engineering, licensed airport engineer in New York, and mathematical models are a hobby.<HR></BLOCKQUOTE>

Excellent. I’m a registered C.E. in the State of Oregon and Washington, and am considering doing California as well. However this requires a tad bit more than simple reciprocity paper work. I haven’t worked on any airports but have done a fair bit of pavement design (AC and concrete).

Question Rexford: I have spent a fair amount of time chasing down information on the German TC’s use of hand held range finders in Panzers (like the Sf14Z and EM70 type range finders…and no I don’t mean assault guns). Seems to have been a non-standard practice. Do you have any thoughts on this?

[rexford]

Maybe it is TM 9-1907. The fellow who gave it to me wrote 9-1900, but it is performance of projectiles.

Tigers in Africa had turret top connectors for stadiametric range finder, based on Fletcher's Tiger book.

We believe that 88mm FlaK crews may have carried around range finders, those 1/72 scale kits have a guy looking through a long cylinder that looks like a stadiametric range finder. We figure that this may have added to the fierce some rep of the 88 by getting hits faster. Nashorn crews may have used a range finder on occasion.

We had a stadiametric range finder that we bought that was used to do range estimation error studies. Go out on the street, estimate range to a distant car, and then check it against the range finder. We were really close alot of times.

Bell shaped normal distribution curves resulted, where standard deviation would be about 80% of the average error. 25% average error results in 20% standard deviation, if memory holds. Our spreadsheet developes the bell shaped curve for a crew quality and average ranging estimate error, and then randomly picks a number for the estimation error suffered by a particular shot.

Range finder can get one to within average 5% error on first shot instead of 25%, we call this 5% avg. error "super ace" in our system. At 2000m, "super ace" in Tiger I hits Sherman 30% of first shots, 60% on second try. Average shooting tankers in Tiger I get 5% first, 20% second, 25% third.

Fletcher's Tiger book may have some hit probability stats for British gunners firing at a target from Tiger I. It may have taken several shots to hit the target. I think the results were close to what our rules predicted.

At certain ranges, German crews were also trained that if they aimed at the bottom of the target and set their guns at a certain range, they would almost always hit the target. We have data on this. Something like if you set the range for 900m and aim at the hull bottom with Tiger I, you will ALWAYS hit a target that is so high and so wide.

Using the aforementioned method does away with the need to estimate range to within 25%, and assures high accuracy if a target is within 900m. High % of targets are within 900m.

There were alot of tricks that tankers could use to maximize hit chances.

Here is the data I was looking for. If the Tiger I gun is aimed at the bottom of the Sherman hull and the range is set at 900m, the maximum trajectory height is 1.8m.

So a Tiger using the little trick is guaranteed a first shot hit on a Sherman out to 900m. Ha!

Think of how much faster Tigers can shoot when they don't have to estimate range but simply set the gun at 900m and hit everything in between!!!!!!!!!!!!!!!!!!!

The Germans figured out how to do away with range estimation against fully exposed vehicles and take advantage of trajectory shape.

If a target is at 1000m and the 88L56 is set for 1000m. the maximum trajectory height is 2,3m so some shots would clear the top of a 2m high target, but would still hit a Sherman or T34/85.

If a Tiger I uses normal, boring, paint-by-the-numbers range estimation with 25% average error against a target at 700m,
60% first shot hits against a 2m high target.
Set the gun for 900m and hit it almost every time! Which would you use.

The above method is clearly pointed out in several German tank gunnery publications. The Fibels may also go into it. German first shot accuracy climbs pretty fast if CM goes to this for der panzers.

Here is some more data from the German tank gunnery statistics:

50L60 APC and 75L48 APCBC:
aim at bottom of target with gun set at 900m and hit everything from 0m to 900m that is below 2.0m in height.

88L71 APCBC:
aim at bottom of target with gun set at 1200m and hit everything from 0m to 1200m below 2.0m in height. 100% first shot accuracy out to 1200m!!!!!!!!!!!!!


If would be really helpful if someone could ask German or American tankers from WW II about their first shot hit probability at 500m and 1000m against stationary vehicles in the open. We have tried to refine our system so it is consistent with reports such as presented by Fletcher and other sources, because there is always one more factor that enters into things.

If one can believe the story, British tankers in North Africa were supposed to bail out if the first 88 shot was close, because the second hardly ever missed. This suggests that the 88 Flak crew was cheating and using a range finder.

[rexford]

Had to close down while wife used phone.

The use of the German trick to maximize first shot accuracy by taking advantage of max trajectory height doesn't really assure 100% accuracy between listed ranges, due to dispersion. If target is at 900m and you aim at bottom with gun at 900m, you hit on 50% of hits due to up and down dispersion. Half miss by randomly moving slightly below the hull bottom aim point.

But 50% first shot accuracy for 88L71 with target at 1200m is better than estimating range and ending up with 1st shot hits on 35% of tries. If first shot is a tad low and hits the ground, you increase the gun range and you probably end up with a second round hit.

If Tiger I aims at 900m and target is at 459m, average trajectory height at target location will be the maximum and equals 1.8m above hull bottom. This puts the average shot trajectory on the Sherman turret and about 0.40m below the turret top and 1.8m above the hull bottom (using some quick calculations on a model tank).

Now we'll compute the hit percentage.

78% first shot hit chance if dispersion sends round above average trajectory, and 100% if dispersion is below.

So Tiger I aims at bottom of Sherman using 900m gun input, target is at 459m and "88" scores around 89% first round hits. Hit probability will be higher at 230m and 680m since mean trajectory will be closer to middle of target and random dispersion will not put as many shots over or under the target.

With this method Tiger crews don't have to be as well versed in range estimation procedures. The fact that German gunnery may have declined at end of war indicates that crews may have forgotten what they learned under the stress of combat, or they didn't catch the importance of the method in the first place.

U.S. tank manuals after WW II include the above procedure, and it works really well with 90mm HVAP due to high speed and reasonably small dispersion.

88mmL56 APCR has an average maximum trajectory height of 2m for shots aimed at 1000m range.

88mmL56 HEAT is really slow, 1968 fps muzzle velocity, but would hit a 2m high target from 0m to 700m if the gun aimed at target bottom and range was set at 700m (no dispersion case). With dispersion, the hit % against a target at 500m falls below 100%, but would still be pretty high.

Tiger I supposedly used HEAT against T34's carrying infantry, killing tank and HEAT explosion would eliminate infantry.

(I also deal with pavements, just asphalt concrete. Presenting a paper this march on pavement response to moving and stationary loads, asphalt concrete stiffness may decrease by 80% or more under stationary load)

Our spreadsheet does not currently consider aiming based on max trajectory and target bottom, and we had forgotten about it until we looked in the tables after reading recent messages in this string.

If Germans are on defensive, they might also have time to set range markers in grass or measure distances to known landmarks. Then, when enemy moves by landmark, you have range down pat with high chance for first shot hit. Defensive positions may have more advantages than one might think.

Mines not only may channel enemy but can force them to follow route that defense has plotted really well for range estimation purposes.

If Germans are in woods and trees are alot smaller than usual (different species), enemy may overestimate range since they may estimate range based on perceived size of trees. (Airplane pilots may overestimate perceived distance to runway and aircraft elevation due to pigmy trees).

Defense can be good.

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Rex Said:

The use of the German trick to maximize first shot accuracy by taking advantage of max trajectory height doesn't really assure 100% accuracy between listed ranges, due to dispersion. If target is at 900m and you aim at bottom with gun at 900m, you hit on 50% of hits due to up and down dispersion. Half miss by randomly moving slightly below the hull bottom aim point.<HR></BLOCKQUOTE>

Similar to Battlesight gunnery I reckon in US ARMY. Battlesight would normally be employed either when GPS is not fully functional or weather conditions, fog, smoke, etc prevent the TC from using his range finder…or a rapid engagement situation…snap shot. I’m not sure if M1A1 crews are trained in battlesight gunnery. Anyway the theory was that flat trajectory of armour defeating ammunition (SABOT or even HEAT) gives you a good probability of first round hit +/-200meters from your battlesight range setting. Assuming ranges of less than 1,200 meters for the old 105mm SABOT and 800 meters for 105mm HEAT. Battlesight range setting would in theory be indexed into the ballistic computer before going into action. So if visibility was max’d out at 850 meters…than you would pre-set your ballistic computer to 800 meters.

Tigerfibel goes into an elaborate explanation (with generous use of naked or partially clothed women to emphasize various points) of why range estimation is not quite as critical to good first round hit probability at ranges of less than 1000 meters. So at least in the case of German Tank crews these “gunnery tricks” or battlesight gunnery was somewhat more formalized. The use of unauthorized range finders (ala Sf14z or EM70) could be employed – as you have indicated already – to establish relatively detailed range cards (assuming you are in a defensive mode). I also agree with your point on range stakes etc to further strength a defensive positions by estabilishing ranges to prominent features. Not sure how you could model this in a wargame\sim. Units on defense get some sort of accuracy bonus as long as they remain in their initial starting position?

I have dug through FM17-12 (1943 version) a fair bit and have not found anything similar to Battlesight gunnery being employed by circa-WWII US ARMY tank crews. Perhaps there is something in one of the WWII Tank Destroyer Field Manuals regarding this type of thing? A lot of emphasis on range estimation training in FM17-12. I have read a recent account in “Tank Warfare in the Second World War” relaying a story of US ARMY gunnery skills. The story talks about Sherman Crew training in North Africa. Apparently gunners became proficient at hitting “trunks of trees” consistently by the 3rd or 4th bracketing round out to ranges of 1500 yards.

Interesting write-up from a member of the 704th SPTD Battalion. Kentucy Windage.

<BLOCKQUOTE>quote:</font><HR>Dear Sirs:

Reading in the May-June issue about the increased "lethality and tight ability" of the enhanced M1A2, with its extensive use of digital electronics for target acquisition and target tracking, made me wonder if any younger readers knew how target acquisition and target tracking was done fifty-odd years ago. I would like to quote a paragraph from the combat history of the 704th Tank Destroyer Battalion, Fourth Armored Division, of General Patton's Third Army.

The time was September, 1944, the weapon was the 76mm, high-velocity antitank rifle that armed the M-18 "Hellcat." The gunner was SSG Phillip Hosey. I quote from Phil Hosey.

"Near Nancy, France, between Luneville and Arracourt, we faced a group of German tanks that had taken a position one mile away, across a shallow open valley. Our M-18s were in defilade, facing out over a small hill. Infantry led the way across the valley with three M-4s intermingled. The Krauts let them get halfway across, then opened up with anti-tank fire from woods on the right. They immediately KO'd two M-4s and drove the infantry to the ground. Two Panthers, a Mark IV, and an assault gun came out of the woods and moved across our line of fire at the distance of about a mile. In his position in our open turret, the tank commander, SSG Hicklin, watched their progression through his glasses and called out the range: "Two thousand yards, moving at about ten mph." Our rifle, with AP, had a muzzle velocity of 2,700 fps, so it would take two seconds to arrive on target. The Krauts were moving at fifteen feet per second, which let them travel thirty feet in two seconds. Their lead tank was twenty feet long (from the book), so we led him a good length for a center shot. We laid on and fired. Voila, a hit! It struck two feet in front of his rear drive idler. We then picked the last tank and scored — he began to bum. The two intervening tanks were destroyed by two fast AP shots. So we got two Panthers, a Mark 4, and an assault gun. Our 76mm rifle packed a good punch, even at two thousand yards. We felt that we had the best self-propelled antitank gun in the ETO."

In spite of his Purple Hearts and continued combat-related disabilities, Phil Hosey has provided many important first-hand accounts of his experiences for our combat history of the 704th Tank Destroyer Battalion.

CPT Richard R. Buchanan, 704th Tank Destroyer Bn. Secretary/Historian, 704 TD Bn Assn. Wilmington, Ohio<HR></BLOCKQUOTE>

[rexford]

Very interesting historical info and good insight into actual target lead logic and use.

If target was at one mile, 1760 yards, and 76 gun aimed at 2000 yards, 4 hits in 4 shots would be very difficult. One would assume that the range settings would not be changed after the first shot due to continued success. So four straight hits with the same range setting at 2000 yards.

Even if the panzers were at 2000 yards, 4-for-4 would still be very rare, but it could happen. Once in a lifetime event?

We have 105mm APDS ammo in our spreadsheet for scenario's where Merkava's battle Panthers, and battlesight setting of 1000m for 105mm would probably hit anything inbetween with high accuracy.

From what we've read bracketting was a standard method of zeroing in on a target: shoot high aim lower range, too low then aim inbetween original shot and last miss.

Battleships use bracketting and so do tanks. Panzers use battlesight. And an occasional range finder.

[rexford]

The 88L56 is close to the 76mm on M18. If target is at 1900m and 88 is set for 2000m, shot will be 2m above aim point prior to random dispersion.

Since trajectory is above target and half of dispersion is upward, less than 50% chance to hit a target with a 100m error in range estimation at 1900m. This is why first shot hits at 2000m are very rare, range has to estimated to within plus or minus 50m to get average trajectory onto target.

[aka_tom_w]

Rexford, thanks all your comments.

We would all be very interested in seeing your stats, data and spread sheets.

Have you played Combat Mission?

Do you own the full version?

Have you been conducting any Gunnery Range Tests in CM to see how it measures up to your stats and data regarding WWII accuracy and penetration?

-tom w

[aka_tom_w]

just a friendly bump....

http://www.battlefront.com/discuss/smile.gif

[StellarRat]

In 1.1b24 I've had plenty of misses with Panthers even at close range (less then 200m.) I don't there is any problem here. In fact, I think that they should hit MORE often at close range than they do now, but I'm not concerned.

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Rex Said:

If target was at one mile, 1760 yards, and 76 gun aimed at 2000 yards, 4 hits in 4 shots would be very difficult. One would assume that the range settings would not be changed after the first shot due to continued success. So four straight hits with the same range setting at 2000 yards.

Even if the panzers were at 2000 yards, 4-for-4 would still be very rare, but it could happen. Once in a lifetime event?<HR></BLOCKQUOTE>

Perhaps.

Crew quality is a big factor in assessing gunnery skills. Unfortunately we as engineers aren't particularly fond of intangibles that can't be conveniently graphed or plugged into a conventional formula. Laborer dumps an extra 50 gallons of h2o into a concrete mix on site to make his material more workable. Our compressive strength now goes into the ****ter. Hopefully it wasn't a column or beam.

Crew quality goes beyond "elite or green" crew ratings. Some folks are just very good at gunnery. Some are not. So a company of "Elite" Tigers or "Veteran" Hellcats in which 12 or 17 crews have been well trained, and seen extensive combat does not necessarily ensure every crew in this "Elite" company can castrate a fly at 1000 meters with APCBC.

I have often wondered about the application of SLA Marshall's extensive writings on infantry combat relative to crew served weapons. He talks of the more natural fighters in units bearing the brunt of the actual killing an infantry unit does. This is Marshall's infamous "only 10% to 25%" of soldiers in an infantry unit tended to employ there weapons during a fire fight. I am perhaps going off the deep end here in applying Marshall's stats to tank crews, however one good TC and his gunner may very well represent the majority of a tank platoons combat power. The rest of the folks are still there to become casualties but are, in some cases incapable, of hitting the broad side of the moon at 1000 meters.
"Gunner…Sabot…Moon…identified…fire…on-the-way….short…re-engage".

Panther vs Merkava...Jeeze! You mean 10 Panthers vs 1 Merkava...and its closed terrain http://www.battlefront.com/discuss/wink.gif


[This message has been edited by Jeff Duquette (edited 01-02-2001).]

[rexford]

When Tiger I uses battlesight method against the front of a Sherman (900m range and aim at hull bottom), it will AVERAGE a very impressive 91% hit probability when target range is 100m to 900m (2.2m high x 2.2m wide):

Hit % when target is at indicated range and battlesight method is used:

100m-100%
200m-100%
300m-98%
400m-92%
500m-89%
600m-92%
700m-99%
800m-97%
900m-50%

At 900m average trajectory is at bottom of hull and half the random dispersions hit below the hull.

Trajectory reaches highest point of 1.8m between 400m and 500m, so most misses occur at this point due to upward dispersion and average trajectory is closest to roof.

Above data based on double the test dispersion (doppelte 50% ige streung), so it might be improved upon if crew was very professional and kept things in best order.

This sure beats range estimation, and what is even better is that a high percentage of hits strike the turret front and mantlet, which is often much weaker than the hull (Pershing, M4A3E8, IS-2m with 100mm turret front and mantlet, M4A3(76)W and others).

4-for-4 at 2000 yards with an M18 boggles the mind, but Sgt. York did some things with a gun that can only be explained as instinct, training and growing up around guns. The points in the previous message about some people just being plain good is true. The Aussie who hit a German armored car that was beyond the 2 pounder gun sight range marks seems impossible, but it occurred.

Regarding short range misses, Clint Eastwood in one of his pics explained that the key to gun fighting was figuring out who would make a move first and who knew what they were doing. The rest would get excited, shoot like heck but wouldn't aim and probably couldn't hit, and this is what occurred in a bar room scene ("The Unforgiven" or "Josie Wales"?).


My fathers friend was at Kasserine Pass with other green U.S. troops and when the panzers and nebelwerfers attacked they crouched in the trenches, held their guns above the top and fired blindly. Could this happen to some tankers, unaimed fire under the stress of combat? Street shootings are sometimes like this, alot of shots but few hits because folks don't want to stand still and carefully aim.

For 75L48 using Battlesight, 82% average hits from 100m to 900m target range against Sherman front, with low of 69% at 500m:

100m-100%
200m-100%
300m-91%
400m-72%
500m-69%
600m-77%
700m-89%
800m-90%
900m-50%

Above figures calculated using trajectory curve for each gun developed from German data and twice the test dispersion.

For 75mm L48, Battlesight lowers 400m-500m probability but increases hit probability at longer ranges.

If a tank crew does what they are supposed to do and aims according to the book, they should hit close to 93% at 500m. We thought of holding down %'s in miniatures games to model loaders jamming a thumb, grabbing the wrong ammo and having to go back, last minute traverse corrections, etc. Misses can model reduced rate of fire.

We just came across Potapov's site on Russian armament, and it has "actual" Soviet test data for AP and APBC penetration, at 20% and 80% penetration probability. Really good details are limited to 76.2mm and 85mm guns plus 122mm.

Slope effects look bogus, as T/D increases slope effect goes up instead of down, so data requires close scrutiny before it is held to be dependable.

Site address is long, do "search" on potapov and look for Russian Military Zone. Good info on armor thickness and angles for many tanks, although some of the angles and thicknesses seem too low.

Does anyone have access to dispersion stats vs. range for Panther APCBC. The Desert Fox has provided hit %'s but we need actual lateral (Breite) and vertical (hohe) dispersion (streung) data.

[rexford]

Following is Battlesight accuracy for Panther 75 versus Sherman front, aim at bottom of hull and range set at 1100m:

100m-100%
200m-100%
300m-100%
400m-95%
500m-81%
600m-77%
700m-82%
800m-92%
900m-99%
1000m-94%
1100m-50%

Based on dispersion accuracy with gun aimed at center of target, Panther 75L70 is one of the most accurate guns of WW II in terms of small dispersion, being smaller than 88L56 and slightly below 50L60.

[TheDesertFox]

<BLOCKQUOTE>quote:</font><HR>Does anyone have access to dispersion stats vs. range for Panther APCBC. The Desert Fox has provided hit %'s but we need actual lateral (Breite) and vertical (hohe) dispersion (streung) data.<HR></BLOCKQUOTE>

Have you checked my Panther page? Check out the "Characteristics" section. I guess additional vertical and lateral dispersion data can only be found in the archives by digging through additional Waffenpruefamt data.

The Waffenpruefamt data represent actual battlefield results for a tank which fires on a target from a concealed defense position. (most kills were optained this way. Most times the enemy did neither know what hit them nor wherefrom the shot came). Remember tank engagements are won from the tank that sees the enemy first.

If the german tank formation has to fire while being on the move (attack, delay, meeting engagement, etc..) certain other factors (moral, stress in game terms) reduce the hit %. However german doctrine strongly ephazises leapfrogging or another overwatch tactic keeping at least half of your formation stationary while the other part moves. This gives the overwatching part the ability to calmly fire at everything that moves. Ergo real life hit percentages were more or less in the area of the Waffenpruefamt report. The key sentence is:

"However, the average, calm gunner, after sensing the tracer from the first round, could achieve the accuracy shown as the Practice data"

The key element is to get the distance to the target (which hasn´t changed until today) correct. If you have it correct you have an extraordinary high likelyhood to score a first shot kill, if you haven´t you have to look where the tracer falls and to use "Messer und Gabel". This gives you the correct distance after the 2nd shot.

300m engagements with tanks failing several times to hit the target with consecutive shots are a BIG NO-NO with flat trajectory weapons in tank warfare except your optics are totally damadged.

[Panther page] http://www.geocities.com/Area51/Capsule/2930/pzpanther/pzpanther.htm

[Panther Characteristics] http://www.geocities.com/Area51/Capsule/2930/pzpanther/pzpanther-Charakteristics.html

cheers

Helge

------------------
Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!
- The DesertFox -
Email: TheDesertFox@gmx.net
WWW: http://www.geocities.com/desertfox1891

[Jeff Duquette]

Jentz has the accuracy numbers for pzgr 39/42. I am assuming the numbers Desert Fox gave you are from Jentz's "Panther Quest for Supremacy" (I think that's the title) and represent 50% dispersion zone. Jentz also provides hit probability numbers for doubled dispersion for pzgr 39/42. He goes on to imply that the doubled dispersion numbers represent realistic combat accuracy for gunners who were able to maintain their cool in combat. The doubled dispersion numbers apparently represent hit probability for second and subsequent rounds fired at a tank sized target (2m x 2.5 m I think). The assumption of course being range estimation via bracketing. Dunno what the lateral (Breite) and vertical (hohe) stats for this round are…I will send out some emails to folks that may have this information.

<BLOCKQUOTE>quote:</font><HR>Hit % when target is at indicated range and battlesight method is used:

100m-100%
200m-100%
300m-98%
400m-92%
500m-89%
600m-92%
700m-99%
800m-97%
900m-50%<HR></BLOCKQUOTE>

I am very curious as to your methodology in arriving at the above numbers. Do these values represent first round hit probability? Do they assume no range estimation error? Stationary or moving target? Can you share the function you are employing here f(x)?

<BLOCKQUOTE>quote:</font><HR>Rex Said:

4-for-4 at 2000 yards with an M18 boggles the mind, but Sgt. York did some things with a gun that can only be explained as instinct, training and growing up around guns. The points in the previous message about some people just being plain good is true. The Aussie who hit a German armored car that was beyond the 2 pounder gun sight range marks seems impossible, but it occurred.<HR></BLOCKQUOTE>

Although I don't disagree, I still am struck by AAR's ala the following. Perhaps these are simply the odd uber-mench that have found their nitch in the world. Idiot Savant, Genious gunner. Than again if the first shot from our M18 were a lucky hit the gunner now has the range for the subsequent engagements…half the battle is done now with regards to tagging the additional targets. What was the magnification of the M18's gun sight? 5x?

<BLOCKQUOTE>quote:</font><HR>From Seek Strike and Destroy.

The M-36 would not arrive in Europe until September 1944, but once it reached the front, it proved to be the only American armored vehicle that could match the heavier German tanks in firepower. One M-36 destroyed a Panther with one round at a range of 3,200 yards' and another fired five rounds at a tank 4,600 yards distant, scored two hits, and disabled the tank. The M-36 was equally impressive in the secondary missions. In the direct-fire role, a 90-mm armor-piercing shell could penetrate 4.5 feet of non-reinforced concrete.

From the book: "Freineux and Lamormenil" by George Winter

"I saw a flash from the panzer, the shell hitting the building near the eve of the house, sending debris all over us. The panzer then fired another round and missed, hitting the same area. Returning fire, Graham's gunner got off two or three rounds but was unable to score a hit since the German was in a depression … "I then looked to the right across the valley and saw a flash from another panzer about 2000 yards away. I then gave the gunner orders. "Right front! Right front! Range 2000! Fire! After firing I saw the AP with tracers in direct line, but short. I then ordered the gunner, 'Up 2! Fire!' The second shell went straight into the back of the panzer and it started burning. I was watching it with field glasses and to my surprise saw another panzer move from right to left behind the burning tank. I then gave the gunner orders. 'Left! Up 2! Fire!' The shell went straight in to the rear.""(Winter 34-35)

The advance of the 2nd SS Panzer Regiment along this route was halted partially by the Shermans of Vance and Graham. The 2 M4A1(76)Ws stood their ground and stopped a superior force from advancing into the town of Freineux. At the end of the battle 8 Shermans and 8 Panthers were totally disabled or destroyed.<HR></BLOCKQUOTE>

The first tank in the "Freineux and Lamormenil" story requires two rounds to establish range. Second round is a kill. The second tank is destroyed with one round as range has already been established from shots on the first KO…no bracketing needed. Then again these may both be examples of the extraordinary. No one wants to read the tale of the avg. GI Gunner that missed 4 times at 500 meters. But hay that's what I'm here to find out.

<BLOCKQUOTE>quote:</font><HR>Rex said:

Regarding short range misses, Clint Eastwood in one of his pics explained that the key to gun fighting was figuring out who would make a move first and who knew what they were doing. The rest would get excited, shoot like heck but wouldn't aim and probably couldn't hit, and this is what occurred in a bar room scene ("The Unforgiven" or "Josie Wales"?).<HR></BLOCKQUOTE>

I love this analogy. Unfortunately wargamers would never stand for such a thing being implemented in their games.


[This message has been edited by Jeff Duquette (edited 01-02-2001).]

[Andrew Hedges]

WRT the Hellcats going 4 for 4: it's quite possible that they already knew the range to the German tanks, although we don't have enough background information to know for sure. IIRC, the tanks came out of the treeline, turned 90 degrees, and drove in a line. Thus, if the tankers (or TDers, or whatever) knew the range to the treeline, they would have known the range to the tanks, within a small margin of error.

We don't know how long the tankers were overwatching the infantry, but we do know that they didn't just drive up (they were in defilade, covering a planned infantry assault). So they may have been able to determine the range to the treeline ahead of time, or simply been able to consult a map --military maps do tend to show treelines -- and determine the range from that.

Although figuring out the speed at which the tanks were travelling would take a certain amount of skill.

[Jeff Duquette]

From the opposite end of the spectrum.

<BLOCKQUOTE>quote:</font><HR>Captain Charles L. Davis (US Army) describes the actions of a single Sherman tank in a wartime report from the 1st Armored Division in Tunisia (North Africa) in early 1943: "An 88mm gun came into the platoon leader's vision, about eight hundred yards to the right front, with the gun pointed to his right. He gave 800 yrds to the gunner, and the round was high. He gave 700, and the round was still over. 600 was again high. The German crew began traversing to lay on the tank. About then the platoon leader became a bit frantic and began screaming TOUR!, FOUR!' The next round was close enough to stop the gun, which got off one round that was barely wide of the tank. The gunner polished off the 88 with several more rounds."<HR></BLOCKQUOTE>

You were asking about Panther engagement times earlier. I found this regarding Tiger II loading times. From a 1947 test report by the British Army. Perhaps an experienced Tiger II crew could shave a second or two off the times indicated.

The average loading times per round (in seconds) are as follows:
RACK GUN MAX. MAX.
LEVEL ELEV. DEPTH.
A 9.6 8.2 10.1
B 8.0 8.0 9.3

Ready rack A and B are both located in the turret bulge. Rack A is on the Loaders side of the turret (right side of the turret). Interesting that the near side ready racks required more time than far side. Perhaps the British Army Loader guinea pigs were all right handed.

From Jentz: For the Tiger I the expected performance of a gunner on a practice range was one hit out of three rounds fired within 30 seconds at a tank sized target traveling 20 kilometers per hour across the front at ranges from 800 to 1200 meters. The test parameters were apparently the same for Tiger II crews with the exception that ranges were extended due to the flatter trajectory of the higher velocity 88mmL71. I suspect if this were the US ARMY it would be a safe bet that these would be the test standards for all gunners. With the WWII German Armies seeming fondness for non-standardization it might not be a safe assumption to make that Panther crews trained under the same standards as Tiger I or II crews.

CAT scores for a few tanks…veteran crews (first shot at 1 to 2 km range). Some German general apparently reported that if you add 5 seconds to CAT results you’d get average tank crew times.

M60A3/T72A 14sec +/-5sec
LEO-1 or M60A1 16sec +/-5sec
Battlesight Engagement 12sec +/-5sec
T55/T62 20sec +/-5sec

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>We don't know how long the tankers were overwatching the infantry, but we do know that they didn't just drive up (they were in defilade, covering a planned infantry assault). So they may have been able to determine the range to the treeline ahead of time, or simply been able to consult a map --military maps do tend to show treelines -- and determine the range from that.<HR></BLOCKQUOTE>

Or they may have just gotten luckey with their first braketing round.

[Big Time Software]

Good discussion all!

Jeff,

I was going to relate an example here, second hand from Charles, but you just posted the full thing http://www.battlefront.com/discuss/smile.gif Thanks Jeff for finding AND posting that quote from Captain Charles L. Davis. Perfect example of how important it is to not screw up the range even with a flat trajectory gun.

There is also an account from Macksey's "Tank vs. Tank" description of the battle at Singling between Hellcats and Easy Eights vs. Panthers and Jagdpanzers (not sure what type). It is interesting for several reason (one is that it shows how the Germans racked up large kill tallies), but the one to make note of here is close range accuracy.

Basically, one Easy Eight (Fitzgerald in command) knocked out a Panther at 150m, then missed one at 400m, then killed another at 500m and hit a fourth at 800m without causing damage. Although Fitzgerald was using a "flat trajectory" gun, he still managed to miss at 400m. And since he hit three other Panthers (KO'ing two out of a total of three German AFVs) while almost 20 US AFVs were knocked out, I think we have to assume that Fitzgerald and his crew were damned good.

Steve

[Big Time Software]

Andrew Hedges wrote:

<BLOCKQUOTE>quote:</font><HR>We don't know how long the tankers were overwatching the infantry, but we do know that they didn't just drive up (they were in defilade, covering a planned infantry assault). So they may have been able to determine the range to the treeline ahead of time, or simply been able to consult a map --military maps do tend to show treelines -- and determine the range from that.<HR></BLOCKQUOTE>

Note that we are going to do some changes, possibly for CM2, that will help simulate pre-battle range determination. As I am sure everybody in this thread will agree with, having the time to get a good range BEFORE combat gives that side a critical edge.

Right now only AT bunkers get an advantage for 1st shot accuracy based on this principle. Obviously, such fortifications would have all sorts of landmarks logged and recorded well ahead of any enemy activity. This was easy to add because fortifications can't move during the game. Mobile AFVs are a bit more tricky to deal with, so hopefully we can do something with this in CM2. It is our intention to at least.

Steve

[rexford]

The battlesight hit %'s are based on a gun aimed at Sherman hull bottom and range set at 900m for most guns, 1100m for Panther.

The percentages would apply to all shots taken without changing range or aim spot. Second shots that adjust for misses would increase hit probability.

We put a 2.2m high Sherman (hull bottom to turret top) at 600m, calculated the "no dispersion" trajectory of the gun at 600m when it was set for 900m and then used dispersion to calculate % of shots that fall onto Sherman. Alot of turret hits.

If Sherman height is changed to 2.1m, the scale height of a 1/72 M4A1, the hit percentages drop by quite a bit. Battlesight works best against tanks that are fairly high from hull bottom to turret top. A 2m high T34 would result in 50% accuracy at max trajectory height against most guns, except Tiger I.

We have detailed dispersion data for 75L48, 50L60, 88L71 and 88L56, among others. Hit percentages for single dispersion are for shots aimed at center of target, no range estimation error. Double dispersion shots take into account battlefield impacts on aim but shots are still bunched around center of box.

Since second shots usually contain some degree of range estimation error, the double dispersion hit % would be too high since it is based on an average aim at center of target.

Shots can still hit if range estimation is long, since dispersion can act to bring high shots down to tank level:

If a Tiger I estimates 2000m range and shoots at a Sherman at 1900m, the shot flies over the aim point by 2m without dispersion. Say the target is a 2.1m high Sherman and aim is at vertical center.

Shot flies over top of Sherman by 2m from aim point minus 1.05m from aim point to turret top, or 0.95m.

Since dispersion adds to and subtracts from average trajectory height, we have to consider dispersion. Vertical Tiger I dispersion at 1900m is 50% of shots within 0.9m from average trajectory, or 68.3% within 1.33m.

50% of dispersions will be lower than average trajectory, and dispersion standard deviation is 1.33m (standard deviation represents 68.3% of distribution). 0.95m above turret divided by 1.33m results in 52% of low dispersions missing tank and 48% hitting.

With 5% range estimation error against 1900m target, 24% of shots will hit even though average trajectory is above target. Dispersions can bring bad range estimate shots back onto target or turn a good estimate into a miss at long range.

Tiger I gun has 50% dispersion of 0.9m at 2000m, which corresponds to a standard deviation of 1.33m. If range estimation is perfect and average aim is at center of 2m high target, we have 2m high target divided by 1.33m standard deviation for 1.5 standard deviations. 1.5 standard deviations is equal to 87% vertical accuracy, which is the figure published for 88L56 at 2000m with single dispersion (100% of lateral shots are within 2.5m distance).

If we double the 2000m dispersions, we have 2m vertical distance divided by 2.67m standard deviation, for 0.75 standard deviations within the vertical distance. This corresponds to 55% of vertical dispersion within 2m high distance, lateral % is 91%. 55% vertical spread in box times 91% lateral dispersion results in the 50% overall figure for shots within 2m x 2.5m box when average aim is at box center and shots are subject to dispersion.

Range estimate errors lower percentages by quite a bit, 25% average range error (bell shaped distribution curve) at 2000m results in 5% hit chance against 2m x 2.5m, down from 50% with perfect average aim at center of box.

Tanks with really great gun sights, like 10x Jagd Panther, don't make gunners squint to see where they should be aiming on 2000m shots, which increases hit %. The further one aims from the center of mass, the lower the percentage of hits when range estimation errors are considered. 10x scopes yield a real good view.

Tanks with 1.0x sights suffer compared to 2.5x scopes in terms of increased eye strain, greater variations in aim point, less ability to pick up on fall of shot, etc.

Tanks with 2.5x scopes might represent a standard in CM, which would then suggest accuracy bonus' for 5x, 6x and 10x and penalties for the 1.9x and 1.0x scopes. The less powerful the sight, the smaller the perceived target and the more difficult it is to aim at the center, or at the bottom if one is using battlesight aim.

In our rules, elite or battle hardened vets that take care of their instruments and gun alignment may qualify to use 1.25 times test dispersion for their first shots along with decreased range estimation errors, while average folks use double dispersion and 25% average errors. Good vets in Jagd Panther with 10x scope would certainly qualify for our bonus', while green troops might not know how to take advantage of tank instruments and wouldn't get the same results.

Based on The Desert Fox' Panther site presentation of hit probabilities when average aim is at center of 2m x 2.5m box, Panther 75mm has less dispersion than 88L56 and slightly less than 50L60. When 50mm Pak entered North African theater it immediately increased engagement range due to less dispersion than other guns, better optics and a greater magnification gun sight than 2 pounder (3.0x magnification for 50mm Pak, 1.9x for 2 pounder, 1.0x for U.S. 37mm).

50mm Pak round to round dispersion at 900m is about 60% less than German 76.2 L51.5 and 40% less than 75L48 APCBC.

If one can''t aim properly at a long range target or has a gun with large dispersion it makes sense that one won't hit it as often, and 50mm Pak clearly was a superior weapon with regard to accuracy.

The ability to hit is tied into many factors such as distance estimations, gun sight optics and magnification, weapon alignment and fine adjustment, and if everything else was equal 50mm Pak would probably have a higher hit % than 2 pounder based on gun sight advantages.

[aka_tom_w]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:
Andrew Hedges wrote:

Note that we are going to do some changes, possibly for CM2, that will help simulate pre-battle range determination. As I am sure everybody in this thread will agree with, having the time to get a good range BEFORE combat gives that side a critical edge.

Steve Says:

Right now only AT bunkers get an advantage for 1st shot accuracy based on this principle. Obviously, such fortifications would have all sorts of landmarks logged and recorded well ahead of any enemy activity. This was easy to add because fortifications can't move during the game. Mobile AFVs are a bit more tricky to deal with, so hopefully we can do something with this in CM2. It is our intention to at least.

Steve<HR></BLOCKQUOTE>

OH you know I have to jump in on this one.

May I suggest that for the final v1.1 we could also see dug in Tanks gain the same "advantage for 1st shot accuracy" based on a known range.

And now that we know that an "advantage for 1st shot accuracy" based on a known and established range can and is modeled in the game can we look again at range finders in tanks and range finders associated with the 88mm flak that while not in a bunker "should" give the same "advantage for 1st shot accuracy" based on known range.

I would FULLY support ALL efforts to enhance 1st shot accuracy, based on something that attempts to model the likelyhood (it should be a percentage or an odds calucaltion to determine if the correct range was in fact correctly determined, perhaps based somewhat on crew experience level) of predetermined range to target accuracy.

Stationary tanks which have been documented to have these range determination devices available to them (especially in CM2 on the Eastern front at long ranges) SHOULD have some form of advantage for 1st shot accuracy, based on the use of their range finder as well.

Great thread, Thanks Steve for the updates and comments.

-tom w

[This message has been edited by aka_tom_w (edited 01-03-2001).]

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Steve Said:
Perfect example of how important it is to not screw up the range even with a flat trajectory gun.<HR></BLOCKQUOTE>

Regarding the Captain Charles L. Davis (US Army) N. Africa account this is no doubt a 75mmL31. Both Shot and APCBC have muzzle velocities of 588 m/s. Low velocity very “unflat” trajectory. Battlesight gunnery would be a relatively useless exercise at anything other than very close range. This is apples and oranges relative to an 88L56 or 75L70.

<BLOCKQUOTE>quote:</font><HR>Steve Said:

Basically, one Easy Eight (Fitzgerald in command) knocked out a Panther at 150m, then missed one at 400m, then killed another at 500m and hit a fourth at 800m without causing damage. Although Fitzgerald was using a "flat trajectory" gun, he still managed to miss at 400m.<HR></BLOCKQUOTE>

The 4th AD's Engagement at Singling is classic small unit combat study by the US ARMY and covered extensively (maps, figures and contemporary photos) in “Small Unit Actions” Historical Division US War Department, April 1946. Although K. Macksey covers Singling in “Tank vs. Tank” you really should get “Small Unit Actions”.

According to Fitzgerald’s account his gunner was apparently still adjusting his sights when the second Panther fired a smoke round “and a few seconds later disappeared as effectively as an octopus behind its self-made cloud and escaped”. There doesn’t seem to be any mention by Fitzgerald of actually firing on this tank. Odd, considering the previous detail regarding range and number of rounds fired in the other Panther engagements by Fitzgerald at Singling. However, if he did as Mackey suggests perhaps the target was obscured by smoke.

In addition, Macksey’s reference to the loss of 20 tanks is not referring exclusively to the famous action by Fitzgerald on December 6 around Singling. The actual losses suffered by elements of Task Force Abrams at Singling on December 6 included 5 medium tanks (photos of several of these rittled tanks are shown in “Small Unit Actions”).

The Dec. 6 attack on Singling included Company B/37th Tank Battalion and Company B/51st Armored Infantry Battalion. B/37th apparently had 13 tanks, plus the Company CO’s tank, and the Artillery F.O.’s tank (15 total). Macksey’s British up-brining is obvious from his reference to Artillery F.O.O. tanks http://www.battlefront.com/discuss/wink.gif The final reckoning of the battle at Singling reveals neither a big action nor a startling successful one. All 4th Armored Division units directly involved suffered a total of 22 casualties, of which 6 were killed; they lost 5 medium tanks. Known enemy losses were 2 Mark V tanks and 56 prisoners.” Both Panthers were KO’d by Fitzgerald’s Tank Crew.

A German SP was also damaged by bazooka fire…5 rounds fired…1 hit. The crew apparently abandoned their tank after the hit, although according to the Armored Infantrymen doing the shooting, the bazooka round only succeeded in scratching the SP’s armor. Germans retained possession of the field after the battle, and presumably that is why this abandoned SP isn’t included in the casualty figures.

Anyway Macksey’s 20 tank figure includes several days worth of action by 4th AD in the vicinity of Singling and Binning. Some of these tank KO’s were apparently immobilized because of muddy ground conditions and subsequently destroyed by German Indirect Artillery fire.

<BLOCKQUOTE>quote:</font><HR>While Padgett had been trying to get to Belden, Lieutenant Guild, the observer, had already spotted the enemy tanks himself from the roof of his OP, No. 33, and had informed Captain Leach. Leach took the warning personally to Lieutenant Goble. Goble, figuring that if the Germans attacked they would come either down the road or in back of the houses opposite, had Sgt. Robert G. Fitzgerald on the right move his tank down the hill to within 15 yards of the edge of the road, where he could observe better to the northeast. Fitzgerald kept his gun sights at 1,400 yards, the range to the northerly ridge where the enemy was reported. The first tank to appear, however, drew up between No. 37 and No. 38 less than 150 yards away, heading toward the church. The enemy Mark V and Fitzgerald saw each other at about the same time, but neither could immediately fire.

While the enemy started to traverse his turret, Fitzgerald brought his gun down. He shot first and, at point-blank range, put the first round into the Mark V, setting it on fire. One man jumped out and ran behind one of the houses. Fitzgerald fired two more rounds into the burning tank.

http://www.geocities.com/tigervib_2000/Fitzgeralds_Panther.jpg
Fitzgerald’s 150meter Panther. The Picture was taken from the approximate spot where Fitzgerald’s tank fired from.

Later, on warning by Lieutenant Padgett's infantry that more enemy tanks were approaching from the northeast, he drove his tank through the hedge and east along the road almost to the bend where observation north and east was clear. He saw an enemy tank, but before he could adjust his sights the German fired smoke and in a few seconds disappeared as effectively as an octopus behind its self-made cloud and escaped. Rockets then began to fall close to Fitzgerald's tank. Whether this was aimed fire from the battery near Welschoff Farm or simply a part of the miscellaneous area concentration on the town, Fitzgerald did not stay to find out. He retired westward to the concealment of the hedge, and there, leaving his tank, crossed with Lieutenant Goble to Padgett's CP. From the house they could see a Mark V in the valley " northeast, apparently parked with its gun covering the road east, facing, that is, at right angles to the tankers' observation. Fitzgerald went back to try a shot at it. Again he moved his tank east, getting a sight on the enemy between two trees. The second round was a hit; one more fired the tank. He then shot a round or two at another Mark V facing him about 800 yards away, at which Sgt. Emil Del Vecchio on the hill behind him was also firing. Both 7 5-mm and 76-2-mm
shells, however, bounced off the front armor plate of the enemy. Fitzgerald decided to move back to his hedge. Back in No. 39 again he saw an enemy SP moving east in the vicinity of Welschoff Farm.

Rather than risk exposing his tank again by moving it out to the east, Fitzgerald decided to wait until the SP came around behind the farm and emerged into his field of fire. But the SP did not emerge. Whether, concealed among the farm buildings, it fired into the 1st Platoon tanks cannot certainly be determined. But in any case, a short while after it had disappeared, two rounds of AP hit Lieutenant Goble's tank in quick succession. The first round set it on fire and wounded Goble and his gunner, Cpl. Therman E. Hale. The second round penetrated the turret, then apparently ricocheted inside until its momentum was spent, and finally landed in the lap of the driver, Tech. 5 John J. Nelsen. Nelsen dropped the hot shell, scrambled out, and with the loader, Pvt. Joseph P. Cocchiara, ran from the burning tank.<HR></BLOCKQUOTE>

[Jeff Duquette]

Rexford:

So the spread sheet is presumably a trade secret. Never the less facinating information.

I am picturing the following problem in my head as I am to lazy to sketch at the moment. Does your model account for elevation contrasts between target and firing vehicle. Without sketching this out I am guessing that significant elevation contrasts would change the geometry and size of the beaten zone. I am also guessing that the resultant accuracy for range “X” with a significant elevation contrast would be different than range “X” for the same elevation between target and firing vehicle.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

<BLOCKQUOTE>quote:</font><HR>The enemy Mark V and Fitzgerald saw each other at about the same time, but neither could immediately fire.

While the enemy started to traverse his turret, Fitzgerald brought his gun down. He shot first and, at point-blank range, put the first round into the Mark V, setting it on fire.<HR></BLOCKQUOTE>

I thought this was kind of interesting. Fitzgerald’s initial turret facing was apparently straight down the road shown in the photo above prior to spotting his 150meter Panther. The Panthers Turret was apparently parallel to the same alignment…gun obviously facing the opposite direction as Fitzgerald’s gun. The account indicates simultaneous spotting by Sherman of Panther and Panther of Sherman.

Panther TC: “Gunner…Shot…Tank…Traverse Left…Traverse Left…Traverse left”.

Sherman TC: “Gunner…Shot…Tank…Traverse left…on…two hundred…Identified…up…fire…on the way…ka-boom…cease fire”.

The KO’d Panther still has a full 20 to 30 degrees to traverse before it would be bearing on Fitzgerald’s Position. Look at the angle of the Panthers gun relative to Fitzgerald’s firing position in the photo above. What RPM’s was the Panther’s driver revving his engine at? Beaten to the draw by a country mile.


[This message has been edited by Jeff Duquette (edited 01-03-2001).]

[rexford]

With battlesight aim, aim at hull bottom and set gun for 900m with Tiger I.

Would terrain grades effect shot? Never thought of it, and we hadn't even considered including battlesight until a few messages ago.

Trajectory height is estimated with regard to bottom of target, shooting down a slope would still result in same trajectory shape relative to line between firer and target, so grades might not substantially impact distances. So if target tank is on higher or lower ground than firer it may not significantly change results.

We'll look into this further. Good question.

See message on trajectory model for more on how things work and the assumptions that were made. Trajectory model developed about 13 years ago and we forgot most of what went into it.

Good questions from readers made us open up the old yellow notepads and try to decipher cryptic scribblings.

Somewhere in our storage shed we have a curve for armor resistance to HEAT versus target hardness. Reason why bazooka failed to penetrate Tiger I and T34/85 in Korea was because hard armor increases resistance to HEAT and HEAT must over-penetrate by about 20mm or so to do real damage.

But HEAT hits can scare heck out of crews and make them abandon vehicles. First use of bazooka against panzers (North Africa?) caused hull hatches on PzKpfw IV to blow open but crew and tank interior undamaged. Crews thought bazooka gases were poisonous so they bailed, but later got back in and continued when fellows left behind were not dead.

Side skirts may increase HEAT effectiveness by providing stand-off distance that allows HEAT jet to get organized. Some modern HEAT anti-tank ammo uses pole on end to promote stand-off distance, at least that is what Guard buddies told me.

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>REX: See message on trajectory model for more on how things work and the assumptions that were made. Trajectory model developed about 13 years ago and we forgot most of what went into it.<HR></BLOCKQUOTE>

Saw it and printed it out to read at my leisure. Excellent post as usual. Tanks.

<BLOCKQUOTE>quote:</font><HR>REX: Somewhere in our storage shed we have a curve for armor resistance to HEAT versus target hardness. Reason why bazooka failed to penetrate Tiger I and T34/85 in Korea was because hard armor increases resistance to HEAT and HEAT must over-penetrate by about 20mm or so to do real damage.<HR></BLOCKQUOTE>

I read somewhere that in several cases the M9’s poor performance against North Korean T34/85’s was partially attributable to old ammunition and faulty fuzes. The 24th ID’s Ammo had apparently been setting about in damp storage facilities in Japan since 1945. I have also seen some implication that some\many of Task Force Smith’s and the 24th ID’s bazooka teams were not properly trained and may not have been removing safety pins prior to firing. Never the less, weather it was faulty training or FH armor the ARMY and MARINES quickly switched out to the M20. The M20 was apparently quite effective against T34/85's during street fighting in Seoul following the Inchon landings.

I recently came across an account in “Battle for Mortain” in which a bazooka team fired at a Panther. The tank stopped cold. Bazooka team examines innards of tank and there is no penetration or interior spalling, but the crew are all dead. Concussion perhaps?

<BLOCKQUOTE>quote:</font><HR>REX: Side skirts may increase HEAT effectiveness by providing stand-off distance that allows HEAT jet to get organized. Some modern HEAT anti-tank ammo uses pole on end to promote stand-off distance, at least that is what Guard buddies told me.<HR></BLOCKQUOTE>

Interesting. This is the same stance BTS has regarding ad-hoc armor and HEAT. I’m no expert on the Monro - effect, but presumably the plasma stream is increasing in energy up to its focal point, and decreasing after the focal point. Ideally the focal point is also coincident with the target armor plate face. Panzerfaust, LAW, bazooka, schreack, PIAT, RPG, Carl Gustav etc. would no doubt all have different focal points and would therefore not all be effected in the same way by spaced armor, shurzen, sandbags, logs, tracks, etc.

The old 105mm HEAT rounds for the M48A5 had a long (6inch maybe?) pole on its business end. The pole basically extended out of a flat nose. The flight charachteristics of the thing must have been similar to that of a brick.

Please excuse my stream of conciseness format.


[This message has been edited by Jeff Duquette (edited 01-03-2001).]