TANK GUN ACCURACY AT SHORT/MED RANGE

[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!

[Guest 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.

Its probably about time to start ANOTHER reallly long tank gunnery accuracy thread

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 .

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!

-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

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.

[Guest 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

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....

[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

[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.