88mm KwK 36 L/56 accuracy test and some ideas

[PzKpfw 1]

Actualy this is the data requested in the optics thread, whats needed now as a start is Allied practice range results at the same ranges.

Regards, John Waters

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Notice: Spelling mistakes left in for people who need to correct others to make their life fulfilled.

[:USERNAME:]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Snake Eyes:

I must admit that I quit following the "Superior German Optics" thread when folks started pulling out their flamethrowers. I hope this thread doesn't turn into a 'Five Alarmer' like that one did.

CM is a great game. The best wargame around. The watchword here is GAME. It would not be nearly as much fun if it parodied reality too closely. As a consequence many compromises and abstractions must be included to make it fun. The question is, has BTS tweaked the range issue a little too much? My thinking is, they have. However, I think a small adjustment would suffice.

<HR></BLOCKQUOTE>

I agree. If you read through the first couple pages of that thread, you will see I started an exchange with Jarmo (?) regarding doing tests. I thought it was a good place to start.

Next thing you know, theres gyros, flying M18s, lectures on logic, planes, flames, bermuda triangle for posts, etc.

So lets see what we got and lets see what people think is wrong or right.

Lewis

[aka_tom_w]

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

Just a warning though, thie is a scientifc style report and not a personal attack. This needs to be placed on the table before the flamers come out.<HR></BLOCKQUOTE>

Here, Here!

Lets just keep to the science of testing this thing out.

The Sherms can be "dug in" so they don't move but then you are introducing the variable of Hull down-ness.

I did the same test last night yes you are correct they don't just sit there and look like pretty targets they all squirm around and try to get away, (sorry that was not really scientific way of describeing but that's what they do)

I plan to test Crew and gunner experience if all crew levels of the Tiger I against dug in Sherms with no ammo at 1000 1500 and 2000 meters.

The Hull down nature of the dug in Sherms could be a variable but thats the only way I can think if to keep them from moving while I use them for target practice.

Unless we want to aim at an imbolie anti tank gun or a small house?

comments?

and please,

NO wagering

-tom w

[:USERNAME:]

Is there a way to edit a vehicle size? which vehicle closest fits the standard 2x2.5m (or whatever it is) target? What about a bunker?

Damn I have to go to work. Sorry Steve. Gotta go get my wages and pay my taxes. Including state taxes.

Lewis

[aka_tom_w]

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

Is there a way to edit a vehicle size? which vehicle closest fits the standard 2x2.5m (or whatever it is) target? What about a bunker?

Damn I have to go to work. Sorry Steve. Gotta go get my wages and pay my taxes. Including state taxes.

Lewis<HR></BLOCKQUOTE>

Please,

Lewis Please...

Refrain from taunting and flameing.

I really think we are on to something here

and the idea of using a Machine gun bunker as as testing target may in fact be a VERY good suggestion.

If we are all doing tests we must state our methodology and rational for that methodology.

Shoot at concrete bunkers could be a good idea for target practice.

Lewis makes a good point, what is the Standard target size that those accuracy data on that GREAT page refer to and how can we model or simulate that to test it in CM?

-tom w

[aka_tom_w]

From this web page:

http://www.wargamer.org/GvA/weapons/introduction.html#Gun_Accuracy_Data

"Gun Accuracy Data

The Gun Accuracy tables show the results of two types of tests: dispersion and firing.

Dispersion tests show the percentage of projectiles that will hit a 2.5m ? 2m target during controlled test firing. The pattern of dispersion is assumed to be centred exactly on the target. These results give a good theoretical comparison of guns and ammunition types, without considering the complicating effects of human error.

Firing tests show the expected percentage of projectiles that will hit a 2.5m ? 2m target by a gunner during practice firing on a gun range. It is obtained by doubling the dispersion pattern obtained from the dispersion test data. The British, Germans and Italians all considered this to be a close approximation of the accuracy obtained by troops in practice firings and, if they remained calm, in combat when the range to the

target is known. Due to errors in estimating the range and many other factors, the probability of a first round hit was much lower than shown in these tables. However, the average, calm gunner, after watching tracer from the first round, could achieve the accuracy shown on subsequent shots."

OK, this quote does indeed indicate that there is a strong case to be made for a lower first shot accuracy hit probability.

But again I would suggest CM should model a HIGHER second and third shot accuracy algorythym at ranges over 1000 meter for veteran Crack and Elite german crews.

BUT all the test data aren't in so at this point my suggestion here may still be just conjecture.

-tom w

[This message has been edited by aka_tom_w (edited 10-06-2000).]

[:USERNAME:]

http://www.isa.org/journals/mc/feature/1,1773,146,00.html

It occurs to me that precision is what we are talking about here. And it is directly related to my area of work. And people will argue extensively by what is meant by precision BTW.

Believe me. Repeatability is the hallmark of precision.

Lewis

[aka_tom_w]

Good point Lewis

Perhaps you might take a few minuts to remind all of us (remember I'm only a "slack ass poster boy") of the differences between accuracy and precision.

I know I for one could use a refresher.

Thanks

-tom w

[:USERNAME:]

Well the link above gives what MOST motion control people agree upon. That is, precision is made up of accuracy, repeatability, and resolution. Those three give you precision.

After that, you wouldnt believe the nit pickiness that goes on in the spec-manship. (Ever wonder why I am such a dick?)

But I repeat. Repeatability gives you everything. Especially today with the wonderful computers. If I can achieve repeatability then I can usually achieve whatever I am working at (I am working on a white paper proposal at work where I think I can give my company market dominance just due to the fact that "System Repeatability beats Process Precision". I have worked on nanometer resolution systems BTW. Look up nanometers if you will).

But in WWII, guess what? No computers. They relied on other things.

Anyone guess what these things were called?

Lewis

[Guest rune]

Someone asked for...and I found this...

WO 291/171, "Effectiveness of British anti-tank guns"

Available at:

http://www.britwar.co.uk/salts/salt6.htm

There are several good articles there.

Remember there is a difference in the size of the targets. 1000 yds for the Churchill for example, on a smaller target is 81% while the Germans have it at 93%. The Churchill target is smaller. [The size of a Panther Turret]

Rune

[Bombardier]

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

Here, Here!

Lets just keep to the science of testing this thing out.

The Sherms can be "dug in" so they don't move but then you are introducing the variable of Hull down-ness.

I did the same test last night yes you are correct they don't just sit there and look like pretty targets they all squirm around and try to get away, (sorry that was not really scientific way of describeing but that's what they do)

I plan to test Crew and gunner experience if all crew levels of the Tiger I against dug in Sherms with no ammo at 1000 1500 and 2000 meters.

The Hull down nature of the dug in Sherms could be a variable but thats the only way I can think if to keep them from moving while I use them for target practice.

Unless we want to aim at an imbolie anti tank gun or a small house?

comments?

and please,

NO wagering

-tom w

<HR></BLOCKQUOTE>

How about placing a piece of terrain that is normally inaccessible to tanks (such as a “swamp” tile) under a pre-placed tank during the scenario creation.

This method was used to place AT guns within houses.

I have not tried it yet, but it seems that it should work.

[PzKpfw 1]

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

Someone asked for...and I found this...

Rune<HR></BLOCKQUOTE>

This is very interesting Rune and its a start so we can compare the accuracy to an extent as more data is needed on size of target but thw 76mm is probability of a 1st round hit, we need range data

Regards, John Waters

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Notice: Spelling mistakes left in for people who need to correct others to make their life fulfilled.

[This message has been edited by PzKpfw 1 (edited 10-06-2000).]

[Guest rune]

Actually I would toss out the 76mm data, as it was stated using ammo it never even had! If you are reading the first table that is...

The one that interests me, is firing at tank sized target at different angles and the chance of hitting...for example

The 17 lb gun, firing APCBC on a Tiger 1 had a 50/50 chance of Killing it with the first shot at 2000 yards straight on. The Panther figures must be a typo, proof, look at the 0 degree and 45 degree tables. Should be harder to kill at 45, not a whole lot easier.

Rune

[ASL Veteran]

It is possible in CM to fire at vehicles that have already been destroyed. That would give you a non moving target to fire at for as long as you want to blast away.

[aka_tom_w]

There is a GREAT deal of info here related to what we are discussing.

I have not read it all but this guy sounds like he knows what he's talking about....

from this web page:

http://www.britwar.co.uk/salts/salt5.htm

"This document is a companion document to the WW2 anti-tank gun penetration performance file, and I hope it will prove of equal or greater interest to WW2 wargamers. Its contents are listed immediately after this introduction. This file differs from the ATk penetration file in its wider subject-matter and narrower range of sources. This is because, while information on anti-tank guns is frequently presented in popular works, data on the effectiveness of artillery, small arms and air weapons is much rarer. All sources currently cited here are documents from the PRO, Kew, mostly from the series WO 291, which are reports and memoranda from operational research (OR) sections during and after WW2. Other useful series are WO 231, military training files, and WO 232, papers from the Directorate of Tactical Investigation. Several files from these groups that contain information on the accuracy and penetration of anti-tank guns are summarised in the ATk penetration file. Some papers were published after the end of the war, but are relevant because of reference to WW2 weaponry or experience.

There is a mass of data to be found in the files consulted, and the material presented here has been chosen and points extracted to suit my personal taste and interest in limited available time. I have concentrated on papers that looked as if they might be informative on the effectiveness of artillery, small arms or air weapons; it is not always obvious from the title exactly what a file contains.

Many of the papers concern field trials of fragmentation weapons. In these, wooden (I believe usually pine) board targets were set up, and the fragment impacts on them counted. Results are often expressed in "deep strikes and throughs". Using Professor Zuckerman's wounding criteria, penetration of one inch of wood was considered equivalent to incapacitating a man. "Throughs", obviously, are where fragments completely penetrate the target.

The terms "vulnerable area", "lethal area" and "area of effect", when used in the context of fragmentation weapons, are used interchangeably.

The usual common-sense cautions about the variability of results in real life apply, and in some cases the papers draw attention to the imperfect nature of their estimates. Wherever a passage appears in "quotation marks", it is copied verbatim from the original report.

Imperial units are used in all the source documents, and I have retained them here. In order to facilitate conversion to SI units, a note on conversion factors is included at the end of the document.

As ever, I would welcome comments, corrections or additions by e-mail to John.Salt@Brunel.ac.uk. If you can supply additional information on artillery or small-arms effectiveness, please be sure to include title, author, publisher and year of publication for any source you refer to.

John D Salt 05 Jul 1999"

[Guest Big Time Software]

Hi all, interesting discussion (hey Lewis, congrats on your new job ). First, need to clear up one question that has been asked several times now:

<BLOCKQUOTE>quote:</font><HR>I'm quite sure that CM does not model target tracking between individual shots. Can BTs comment on this? <HR></BLOCKQUOTE>

CM absolutely, and without a question of a doubt, increases the chance to hit with each and every shot that is fired from a gun. It might not be reflected in the % hit figure when the Target order is used. I'd have to ask Charles about that one, but he won't be available to answer it for a couple of days.

We also did not "dumb down" any particular weapon arbitrarily. Instead, we looked at a whole bunch of battle descriptions, which actually made note of misses, and came up with our own "battlefield" probability to hit. It might not be exactly correct, but it is at least consistant internally.

In general, remember that test range numbers are done under rather ideal conditions and not battlefield conditions. In CM the gunner is trying to fire pretty much as fast as he can. On a range, unless the test parameters state otherwise, great care is taken with each shot, which would increase accuracy quite a bit. Not to mention that the test gunner was not being fired upon or worried about unknown threats suddenly popping up from nowhere.

There is also the problem of the TacAI taking over and either moving or popping smoke during the test. If this should happen it will totally throw off the numbers since test range data is not against moving or obscured targets. Weather and partially broken terrain also factor in here, but they can be rulled out by using Clear weather and putting the targets on pavement (I would think).

There is also the size of the target. The Tiger, King Tiger, and Panther are all bigger than the Shermans. 20-30% bigger. Therefore, all else being equal, the numbers vs. one of these German tanks should be adjusted down 20-30% (very, very rough guess at reduction). Also, vehicle facing is factored in, so if the Panther turns to the side it will present an even larger target for the Allied gunner.

And don't underestimate the power of the 17lbr. It is a very capable weapon and is a match for the 88L/56. This is realistic.

Bottom line... I am NOT going to say that CM is perfect and there is no case to be made for a numbers tweak. However, trying to compare unadjusted real world test range firings to CM battlefield results is a tough thing to do. As everybody knows, comparing two different sets of tests, done under different test conditions, inherently can not be compared against one another as is.

Just more food for thought

Steve

[aka_tom_w]

Steve says:

"CM absolutely, and without a question of a doubt, increases the chance to hit with each and every shot that is fired from a gun. It might not be reflected in the % hit figure when the Target order is used. I'd have to ask Charles about that one, but he won't be available to answer it for a couple of days."

For any here who doubt this it came up long ago. In this thread:

http://www.battlefront.com/discuss/Forum1/HTML/004572.html

And the answer has been clear that CM does indeed model an increased chance to hit on the second and third shot. But it is still a percentage or a probabililty and without doing ALOT of testing and tabulating the results of every round fired we really can't "see" what that increased second and third shot hit probability is because the game doesn't tell us.

I'm sure that the game does model an increased chance to hit on the second and third shot, but it has been my position since the gold demo that for veteran crack and elite German crews at distances above 1000 meters for the hig velocity rounds these second and third shot chance to hit percentages should be tweaked up a little more.

And this is not really news either.

-tom w

[This message has been edited by aka_tom_w (edited 10-06-2000).]

[This message has been edited by aka_tom_w (edited 10-06-2000).]

[aka_tom_w]

here's something new that might help folks here doing research:

The Wargames and Military Search Engine, http://www.britwar.co.uk/search/

The Wargames and Military Banner Exchange, http://www.britwar.co.uk/support/

Join our communities at: http://community.britwar.co.uk/

just a thought

-tom w

[Kingfish]

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

(Ever wonder why I am such a dick?)

Lewis<HR></BLOCKQUOTE>

Anyone need a sig?

[ASL Veteran]

I would like to see Allied and German gunnery tests on a range compared to each other, and gunnery tests between Allied and German guns in CM compared to each other. We can then compare real range tests to real range tests and CM gunnery to CM gunnery. We then note any differences between the various nationalities in the real tests and see if those same differences are reflected in the CM gunnery tests.

[The DesertFox]

<BLOCKQUOTE>quote:</font><HR>And don't underestimate the power of the 17lbr. It is a very capable weapon and is a match for the 88L/56. This is realistic.<HR></BLOCKQUOTE>

Oh yes it is. A deadly gun!

And BTS is doing good if you have it in the same group as the 88L56 and the 75L70.

Cheers

Helge

PS: I hope this thread remains as constructive as it is.

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Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!

- The DesertFox -

Email: desertfox1891@hotmail.com

WWW: http://www.geocities.com/desertfox1891

[:USERNAME:]

Somewhat quiet here.

I was hoping the discussion would develop as to what is accuracy, repeatability, etc but it hasnt. I am amazed at how sometimes people discuss things and its never established what is being discussed. Even something like accuracy means different things to different people.

Let me put this question out:

Which weapon would you rather fire in combat? One that can hit a 1m by 1m target 15 percent of the time at 1200meters or one that can hit a 2m x 2m target 25 percent of the time at the same range?

Just discuss. Not saying theres any data or anything needed to discuss.

Lewis

[:USERNAME:]

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

What I'd like to see is a graph of the trajectories of the various guns to see how they varied. How much did a Sherman 76 round drop at 1500m and how much did the L56 and L71Tiger, Panther, Mark IV Special, 17 pounder, etc? If there is a big variation then I would assume the guns with 'more loop' need BETTER sights and a more accurate estimate of range or they are going to be much slower at getting hits, all the other variables being equal.

Another factor, if the Allied guns have to use Tungsten to kill at that range and use AP to bracket, does not the Tungsten have different flight characteristics and less accuracy at long ranges?<HR></BLOCKQUOTE>

I could figure out the flight path and calculate the time of flight, length of travel (the arclength if you will), the shell path height (I assume that you want to hit a target at a similar height to the gun that is firing).

[Bobbaro]

Lewis, it seems to me that the smaller target taken 15 percent of the time is the better choice.

On your 4 square meter target that would get you and equivalent of 15 percent on each square meter x 4. The other deal would get you flat 25 percent. While I doubt the math would exactly match the intuitive 60 percent of hits on the larger target with the 15 percnet accuracy I think that would likely represent the direction of the trend.

Obviously a number of the misses at the smaller target would get on to the larger one to increase the hits over 15 percent. A lot could depend upon the causes of the misses though. Assuming all factors equal, though, I still think I would take the 15 percenter.

Now I have bitten, so what do you say?

[This message has been edited by Bobbaro (edited 10-06-2000).]

[virtualfreak]

I am not sure if this has been done or not but I think it would be intresting to see the 88mm tested on several versions of vehicals (spelling?) and light tanks at about 1000m.

Because if an 88mm or even a 75mm for that matter hit near the tracks of a certain vehical it would as we all know disable it or cause the crew to panic.

I also believe expeirience plays a crucial factor on the accuratcy of the 88mm. I would like to see test done on green units and elite units to measure out the accuratcy diffrences.

P.S. I know my spelling is bad so please dont comment.