Long 88mm lacking punch?

[The DesertFox]

Steve,

Cool argumentation

Someone might want to contact RHEINMETALL, I bet they are interested in a formula which can save them money for penetration firing trials.

Seriously,

The reason for development of the 88L/71 was to go to the maximum limit of penetration possible at a given caliber. You really think they developed a gun back then which brings essentially the results your formula produces ?

Well, I take the liberty to doubt that, because it is NOT only the results of the WaPruef reports which are quoted by Jentz which show otherwise but there are additional published data for the 88L/71 available which are basing on independent tests. Bottomline is that all these firing trials give the 88/L71 a performance which is within milimeters of the WaPruef reports, with one [AFAIK, I could have missed some reports here ] exception. That is the 1975 Bovington report, which gives the 88/L71 more or less exactly the performance your formula is calculating.

Now the question remains, Is it that your formula is correct and several firing trials have produced wrong results or is it that your formula is incorrect and the Bovington´75 report publishes wrong results ? Compare the 75L/70 results I have quoted above.

However I feel we won´t change the matter here. Bot sides have their arguments and seemingly aren´t willing to accept the points the other side has made.

But one more remark you might want to check. It occurs to me that the 76L/55 US M1 gun you have in the game is more like a representation of the 76/L62 on the Walker Bulldog which was built in the 1950's ? Why is that ? I could be wrong of course

And please don´t misunderstand all this talk about the game as an attempt to smash it. No that isn´t the intention. It merely is a sign that we all love this game and want it to be as close to realism as possible. You know if we don´t find some big bugs to pick at we start to analyze the details.

Helge

------------------

Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!

- The DesertFox -

Email: desertfox1891@hotmail.com

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

[Paul Lakowski]

I think you all need desperatly to get a hold of some modern engineering journals like the 'Int. J.Impact Engng ' or the 'Int. Symposium on Ball'.

Charles Anderson Jr has lead over a decade of research perfecting a simple penetration formula that currently covers penetrators with L/d of 5:1 upto 40:1 ranging from striking velocities of 800-1000m/s right up to 1800 m/s.

Its prediction ability is baced on lenght and is uncannly accurate and is universally accepted as the method to anaylse all penetration.Its only a matter of time before the research is expanded to include shaped charge and AP type penetration .

For my part I'm going to see if it can be adapted to include APDS and then APC .

I will ask about falsified 88 data ,but in the end I'm sure I'll find that all the data points can be put on a regression line just by finding out things like plate dimentions in relation to projectile dimentions or adjusting for projectile shape.

I did some preliminary measurements and the 88 seems to have tip to rod diameter of ~ 6-7 :1 which is markedly different than other APCBC[ ~4:1]. It also may be that the penetration abilities of HVAP and APDS may be more tied to this factor as there ratios are in the 14:1 range.

I wish you luck with your game as it seems to be reviving the wargaming industry along with our game 'Steel Beast'.

[Guest Big Time Software]

Helge, if you have two sources and we have two sources I fail to see why you feel so confident that you can choose one and call it right (and ours wrong) wihtout any other reasoning other than "I like it better". That isn't very scientific when compared to our mathematical model that not only is backed up by one 88L/71 test result but also matches all the other test results.

Paul, It would be VERY enlightening to see what the formula you are in possession of produces for penetration stats for the 88L/71 and other WWII based German guns. I for one would love to see how it could have a totally different result for one piece of data even though it is similar to others.

Also, Charles asked you to cite the source you mentioned. We would like to look at it and see exactly what it has to say.

Steve

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Simon Fox:

Lakowski, Waters et al in their arguments cite data from the review publications by Jentz and Hogg among others to support their hypothesis that the formulae does not adequately model the 88L71 gun performance. They fail to cite the primary sources for this data. Nor do they cite the actual methodology used to perform the tests including the experimental design and the materials. Furthermore since they do not cite the primary source for the data it is impossible to properly judge the scientific credibility and integrity of the individuals and/or organisation which originally published the data. Since it appears that no other comparable data is available for this gun (?) and it is clearly impossible to repeat these experiments I beleive that they have provided insufficient argument to support their hypothesis. It may be that they are correct to question the validity of the formulae used. However, as it now stands it accurately predicts all of the properly documented experimental data. I would hope they can provide further evidence to support their argument.

<HR></BLOCKQUOTE>

Simon, you are incorrect in that primary source material has not ben cited.

All the German penetration data was complied by the Germans during WW2, Ie Jentz's data is extracted from actual German test data from Wa Pruf, & Waffenamt test reports etc.

Charles knows where the data came from and agrees with it except for the L/71 8.8cm ammunition performance, nor is he challenging Jentz etc, data he is challenging the German wartime test data used as primary source material in the books.

The test process has been generaly outlined by me here in posts along with cited British test data for the same ammunition etc,as examples.

<BLOCKQUOTE>quote:</font><HR>The burden of prooveing (sic) that the 50yr old 8.8cm L/71 German wartime test data is valid has been laid on ppl who disagree or don't know who is correct.<HR></BLOCKQUOTE>

Simon have I stated on this board that the 8.8cm L/71 penetration test data is incorrect?.

The answer is no I never claimed that it was wrong or that it was even correct. Charles publicly called into question the 8.8cm L/71 penetration data based on his knowledge of physics, and useing the British 1950 penetration report curve data.

It seems logical to me that if I make a public claim that is contrary to primary source material or a preponderance of documentation; that its up to me to provide empiracal evidence to support that claim.

Not pass it off to prove or disprove on ppl who disagree or don't understand, in this case the burden of proof that the German wartime penetration KwK.43 ammunition test data is flawed lies with Charles.

I have also stated I see Charles point concerning the curve between the penetration data diference concerning the Kwk.42 L/70 & Kw.k 43 L/71 ammunition.

My interest in this matter is that I want to find out the truth on data that has been accepted at face value, I do not care whom is right or wrong only that a conclusion be reached & I can add it to my knowledge and pass it on to others.

Charles is the first person I have seen openly challenge German wartime test data.

I have also contacted friends and supplied the URL here so they can read Charles reasoning on rejection of the Kwk.43 ammunition penetration data post; so hopefully we will get some more input.

Below are some more examples of German fire test methods below again:

1947 BIOS - British Post-war Analyss Of German Armor Industry

Section IV: Fireing Trial Performance p.227

"Director Dorfmuller stated in broad terms that a 23mm plate face hardened by the induction process was equivalent to a 40 mm homogeneous plate. Plates of 30mm thickness were attacked, he stated, with 20 mm shot velocity 860/870 meters per second, at 15^ incidence. Over-matching was with the same weapon and acceptable back damage was limited to 40/50 mm. Plates 50 mm thick were attacked with 37 mm shot."

Jentz Thomas L. Germany's Tiger Tanks p.9 Data

"The target material used to test German armor-piercing projectiles consisted of rolled homogeneous plates with the following hardness values:

Plate thickness - 80 - 120mm

Hardness (kg/mm2) - 95 - 105

Brinnel Number - 279 - 309

Plate thickness - 121 - 150mm

Hardness (kg/mm2) - 80 - 90

Brinnel Number - 235 - 265

Excerpts as stated in the German manual on armor penetration curves:ibid p.11

"Basically all penetration data are valid for projectiles of good quality. The estimate of penetration for "worst" projectiles is possible only with the greatest difficulty. The penetration can spread over a very large range below the given value.

The regulations for acceptance of projectiles stipulate that a certain number of projectiles (1/2%)will be presented for inspection. Two-thirds of the projectiles which have been fired against armor plate, must satisfy the given conditions. Based on past experience, it can be stated that the largest part of the deliveries satisfy these conditions.

A 100% insurance is not given; it may always be expected that a small percentage do not achieve the specified penetrating ability because of shattering prematurely. Also the explosive charge in these shattered projectiles will not detonate.

The effect of the projectile inside the tank and the probability of hitting the target are not considered in these graphical charts; thus only the complete penetration with total effect inside the tank is considered. As a rule, this effect is of anniihilating power when useing armor-piercing shells with high explosive charge.

The effect of penetration against cast armor parts is under otherwise equal conditions, usualy somewhat higher then against rolled plates. That is not the case if the quality of the cast armor is good. Plates hardened on the surface offer the projectile difficulties only if they cause the projectile to break. If that is not the case, the resistance might be equal to or even lower then homogeneous plates."

Now the above does shed some light on German test methods, and ammunition used in the tests standards. I will dig thru my files and try to locate more data on procedures as well.

Regards, John Waters

---------

"Go for the eyes Boo, go for the eyes!!"

[This message has been edited by PzKpfw 1 (edited 08-24-2000).]

[The DesertFox]

<BLOCKQUOTE>quote:</font><HR>if you have two sources and we have two sources I fail to see why you feel so confident that you can choose one and call it right (and ours wrong) wihtout any other reasoning other than "I like it better". <HR></BLOCKQUOTE>

Steve,

You may not want to realize it but your above statement holds true vice versa as well

To the sources: You find them all in this thread, but the detail analysis is YOUR work. I only can point you in the correct direction. If you want to go the other way, well fine, after all it´s your game.

<BLOCKQUOTE>quote:</font><HR>That isn't very scientific when compared to our mathematical model that not only is backed up by one 88L/71 test result but also matches all the other test results<HR></BLOCKQUOTE>

Scientific ? No Steve please don´t let us go this way. Don´t tell me (I´m Scientist and working in R&D for years now) what is scientific and what isn´t. You don´t want me to say if I think your attitude towards the matter in discussion can stand scientific standards, want you ?

The problem with your mathematical solution is that it doesn´t seem sufficiently refined to descripe real world events. You don´t want me and others to dig into the other penetration results which are produced by this formula and compare them with real world results, want you ?

The problem here seems to be that your formula is underestimating the complexity of penetration events. At least it isn´t possible to describe ALL real world results with it. That´s no big issue for me, because as I have stated above, If someone can come out with such a formula which sufficiently accurate can describe real world results that would make this man a real rich man, because this formula would make firing trials obsolete.

But as stated previously I don´t feel we will come to an agreement here at least until one side or the other will be convinced. As it is right now I totally fail to see any proof (that is necessary here) for your claim that the german 88L/71 WaPruef reports and the other test results are wrong.

Helge

------------------

Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!

- The DesertFox -

Email: desertfox1891@hotmail.com

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

[This message has been edited by The DesertFox (edited 08-24-2000).]

[The DesertFox]

<BLOCKQUOTE>quote:</font><HR>Not pass it off to prove or disprove on ppl who disagree or don't understand, in this case the byrden of proof that the German wartime penetration test data lies on Charles.<HR></BLOCKQUOTE>

100% agreement here. Otherwise you can claim the earth is a table and have others to bring the proof it isn´t.

Helge

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>You may not want to realize it but your above statement holds true vice versa as well <HR></BLOCKQUOTE>

True, if both sides were equal, but they are not. Simple facts...

Test results can not be rellied upon as the WORD OF GOD when compared with other tests. Wait to we get to the Eastern Front. Do you think we are going to base our stats on the Soviet tests? You would appear to think we should

We have solid equations that are based on physics and ballistics research. These equations are backed up by all test data, including the 88L/71 as reported by Aberdeen.

If you look at our equations and the results you can not explain away the 88L/71 as our mistake without saying that all the other data that it produced is also potentially screwed up. And since that data matches the test sources, that would be a bit hard for you to do.

I feel like I am arguing with a brick wall here. Look, it is very simple. If our equations got the 88L/71 wrong they would have got other results wrong. The fact that this did not happen, and we have at least ONE source that supports our numbers, I ask again... on what basis do you have to claim that our math, scientific approach, and test data is no match for your test data and personal conviction?

Steve

[Guest Big Time Software]

John,

<BLOCKQUOTE>quote:</font><HR>It seems logical to me that if I make a public claim that is contrary to primary source material or a preponderance of documentation; that its up to me to provide empiracal evidence to support that claim.<HR></BLOCKQUOTE>

Setting aside all my other evidence for the moment, I think that a simple look at Helge's posted 88 L/71 figures proves that at least some of them are fishy for the one simple fact that they do not agree with one another.

That fact alone should send up a warning flag. I do not understand why you, Helge, and Paul completely skip this fact. I posed this to Paul earlier and I will say it again: even if I were to accept some form of test data for the 88 L/71, which one should I pick? They're all different!

You, Helge, and Paul have based the bulk of your arguments on an implicit assumption that is false: that there is one, consistent set of 88 L/71 test data. Clearly, as one can see from Helge's earlier post, no such consistent set exists. I don't know how you all can continue to ignore this critical fact.

<BLOCKQUOTE>quote:</font><HR>Below are some more examples of German fire test methods below again:<HR></BLOCKQUOTE>

This are all interesting but none of it is part of the contention in this thread.

Helge,

<BLOCKQUOTE>quote:</font><HR>I only can point you in the correct direction<HR></BLOCKQUOTE>

Which direction is that? To the Wa Pruef numbers? Or to the Bovington numbers? They're not in the same directions, you know. Or maybe over to the WO219 numbers? They're in yet another direction entirely. Hogg? Something else? So many directions, Helge - using the very data that you posted. Since they cannot all differ and yet all be correct, this implies that at least some of them are incorrect. This is basic logic. How can you ignore that fact? How can you continue to accept them all as "correct" when this is a logical impossibility? If you disagree here, please state your logic clearly.

<BLOCKQUOTE>quote:</font><HR>Not pass it off to prove or disprove on ppl who disagree or don't understand, in this case the byrden of proof that the German wartime penetration test data lies on Charles.<HR></BLOCKQUOTE>

And I've done so, using the physics and formulae described earlier. The 88 L/71 test figures are highly suspect because they:

1. Don't agree even with one another (how many times must I remind you of this before you acknowledge it?)

2. Are an "outlier" compared to every other gun in CM - those that have lower muzzle velocities than the 88/71 and those that have higher velocities. It is only the 88/71 that stands out. And so far none of you has provided satisfactory proof as to why this is so.

Your data, which is the only evidence you have, is therefore highly suspect. Mine, based on the formulae, is certainly not perfect. But it's a lot closer to the truth than what you would have me use. In fact... what would you have me use? The 88/71 test numbers are all different!

Please do not continue to dodge this issue as it is central to the problem. Your 88/71 test data are not internally consistent, which makes them dubious. If you refute this, please state your logic for doing so. If you dodge this question yet again then it is clearly pointless to continue debating you.

Your data is suspect, and mine is at least reasonably believable considering that it does match up with virtually all test data that I've come across, even for guns faster than he 88 L/71. Therefore I have made a successful case. If you wish to refute it, I invite you to do so. So far you have not been able to do so other than to state that you really really think the published numbers are correct. But you have shown no evidence why that is so. I have demonstrated my point. Now it's your turn.

Charles

[howardb]

If you got 4 reliable sources which doesn't differ too much can't you just compare them and pick a sensible middlepoint? I mean no gun was exactly like the other anyway so this can't be 100%. I don't like the "heinz mm guide" is better than "Johns armor penetration book" because they both could be right when they wrote them.

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>Otherwise you can claim the earth is a table and have others to bring the proof it isn´t.<HR></BLOCKQUOTE>

Cripes man, did you really think about this when you wrote it? We aren't the ones that are blindly regurgating data without critical thought. What you are saying is that you will believe, with BLIND FAITH, anything you read vs. a critical and scientific annalysis *AND* differing credable data that is in support of it?!? Good lord... what the Hell am I doing here wasting my time here for.

Helge, go back and look at my M1 Carbine example. I did a test. I wrote up results. So I guess my results are accurate and are beyond questioning? Your statement would suggest so.

Steve

[The DesertFox]

<BLOCKQUOTE>quote:</font><HR>I feel like I am arguing with a brick wall here<HR></BLOCKQUOTE>

Seems like we are feeling the same here.

<BLOCKQUOTE>quote:</font><HR>I did a test. I wrote up results. So I guess my results are accurate and are beyond questioning? Your statement would suggest so.<HR></BLOCKQUOTE>

No the results are correct. Your reasoning isn´t. That is!

Compare and normalize all published penetration data for the 88/L71 and find out which differ and which don´t. You easyly will be able to find out that only your artificial data differ and the Bovington´75 data. Now what is your reasoning ? All data are wrong except your artificial ones and the data from Bovington ?

<BLOCKQUOTE>quote:</font><HR>Good lord... what the Hell am I doing here wasting my time here for.<HR></BLOCKQUOTE>

Exactly the same am I asking myself

Helge

[PzKpfw 1]

I think the problem here is that we need to seperate Combat Mission from this discussion.

This discussion no longer concerns CM and has not for awhile.

The point of contention here is: Charles public statement that The German Wa Pruf Waffamt: wartime data used by Jentz concerning penetration results obtained in LF tests of KwK.43 annunition is flawed. All signifigant data of these tests has been supplied as well as the outcome.

To date neither Charles or Steve has suplied hard data to substanite this claim. Formula or otherwise, and passed the burden of proving the validity of the claim onto whomever disagrees with the statement.

That is whats under debate here,not BTS's formulas or other penetration cases Ie, Aberdeen, Bovington etc, they are irrelevant to this discussion.

Their is a bigger issue here apperently no one sees but me, if the 8.8cm data is flawed then ALL German ammunition test results are flawed as the same criteria was used for all German ammunition.

Another thing ppl need to realise by questioning this we are not attaking Charles or Steve or CM, we are looking for the truth.

Regards, John Waters

---------

"Go for the eyes Boo,go for the eyes!!".

[The DesertFox]

<BLOCKQUOTE>quote:</font><HR>Their is a bigger issue here apperently no one sees but me, if the 8.8cm data is flawed then ALL German ammunition test results are flawed as the same criteria was used for all German ammunition<HR></BLOCKQUOTE>

Exactly that is the issue we have to solve. [but I fear we won´t be able to]

For subtantiating that claim hard facts are necessary and not artifical gameengine mathematics, may they produce 80% correct outcome compared to LF testresults or not.

You have hit the nail on the head [as we say in germany].

Helge

[Guest Big Time Software]

Helge,

<BLOCKQUOTE>quote:</font><HR>Compare and normalize all published penetration data for the 88/L71 and find out which differ and which don´t. <HR></BLOCKQUOTE>

OK, let's do that. I'll use the data you posted. Here it is:

<BLOCKQUOTE>quote:</font><HR>______CM_____Jentz_____Hogg____Bovington´75____WO185____WO219

range

100m 177mm 202mm

500m 165mm 185mm 182mm 167mm 184mm 178mm

1000m 151mm 165mm 167mm 153mm 169mm 140mm

2000m 121mm 132mm 139mm 139mm 121mm

<HR></BLOCKQUOTE>

Jentz and Hogg are the closest ones to one another. They are similar at 500m and 1000m, but start to differ significantly at 2000m (by 5.3%).

WO185 differs even more from Jentz beyond 500m. At 1000m the difference is 2.4%, and at 2000m it's 9.1%!

Oh boy now we get to WO219 which is different from everybody. Comparing to Jentz, we get a 3.8% difference at 500m and a whopping 17.9% difference at 1000m. This is HUGE!

And I haven't even mentioned the Bovington numbers yet. So stop acting as if the Bovington numbers are a single outlier. Clearly - and we're using the data that you provided, Helge - none of these data sets agree. The other four are not close to one another. Some of the differences (up to 17.9%!!!) are major.

Is 17.9% enough variance for you to consider it significant, Helge? How can you overlook a difference that large?

In fact, WO219 gives a penetration value at 1000m for the 88 L/71 that is less than the value given in Combat Mission! If I am to take you at face value and "just use the published figures" then perhaps I should choose WO219 and lower the capability of the 88 L/71 in CM even further? By your reasoning, this is what I should do.

To sum up, the published figures - not even considering the Bovington data - are NOT close to one another. They do NOT agree.

Even your own figures clearly indicate that you are wrong.

Charles

[This message has been edited by Big Time Software (edited 08-24-2000).]

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>The point of contention here is: Charles public statement that The German Wa Pruf Waffamt: wartime data used by Jentz concerning penetration results obtained in LF tests of KwK.43 annunition is flawed. All signifigant data of these tests has been supplied as well as the outcome.

To date neither Charles or Steve has suplied hard data to substanite this claim. Formula or otherwise, and passed the burden of proving the validity of the claim onto whomever disagrees with the statement. <HR></BLOCKQUOTE>

John,

I will simply repeat what I said above, because I think you must have missed it:

<BLOCKQUOTE>quote:</font><HR>Setting aside all my other evidence for the moment, I think that a simple look at Helge's posted 88 L/71 figures proves that at least some of them are fishy for the one simple fact that they do not agree with one another.

That fact alone should send up a warning flag. ... You, Helge, and Paul have based the bulk of your arguments on an implicit assumption that is false: that there is one, consistent set of 88 L/71 test data. Clearly, as one can see from Helge's earlier post, no such consistent set exists. I don't know how you all can continue to ignore this critical fact.<HR></BLOCKQUOTE>

The 88 L/71 data are clearly suspect, from the simple fact that they are internally inconsistent to a considerable (17.9%) degree. Please do not continue to dodge this critical issue. I have stated it over and over and yet you still dodge it and say that the burden of proof is mine. But I have given far more evidence here than any of you. Now it's your turn. So far all any of you have been able to offer is blind faith in the printed word. Nothing more. If you want me to believe you, you'll have to do a lot better than that.

Charles

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>To date neither Charles or Steve has suplied hard data to substanite this claim.<HR></BLOCKQUOTE>

ARGH!! Not true!! What about the Aberdeen data?!? What about scientifically derrived results that match litterally dozens of other data sets without further exception?!? How can you just dismiss this out of hand and yet offer NOTHING on your side other than "I have chosen this one set of data and, based on nothing other than personal prefference, know in my hear that it is correct and you are wrong"

<BLOCKQUOTE>quote:</font><HR>Formula or otherwise, and passed the burden of proving the validity of the claim onto whomever disagrees with the statement. <HR></BLOCKQUOTE>

That is what YOU are doing. We have step by step provided our case as to why this data is incorrect. We have presented scientific, independently derrived data that matches every other credible data penetration set. YOU HAVE DONE NOTHING to refute these findings other than to say "poppycock".

Again, why aren't you picking the Aberdeen data as the Word of God? What is your reasoning behind this decision? There are three sets of data for the 88L/71 one to choose from. What makes you so sure that you chose the right one?

<BLOCKQUOTE>quote:</font><HR>That is whats under debate here,not BTS's formulas or other penetration cases Ie, Aberdeen, Bovington etc, they are irrelevant to this discussion. <HR></BLOCKQUOTE>

What the heck are you talking about? We have provided a strong scientifically and logically based case for our numbers. You have not. Worse, you have dodged all the direct questions we have posed above. Dodging is a clear sign that you don't have a case, or at least can't make one yourself.

<BLOCKQUOTE>quote:</font><HR>Their is a bigger issue here apperently no one sees but me, if the 8.8cm data is flawed then ALL German ammunition test results are flawed as the same criteria was used for all German ammunition.<HR></BLOCKQUOTE>

This is so frustrating because you are either not reading or comprehending our case. We have addressed this several times. It would appear, for whatever reason, that the 88L/71 data that you are citing is flawed. Why? Because we have a scientifically sound method that shows that all other German weapons match the test data EXCEPT for the 88L/71 of one or two of threee noted examples.

Again, this is an all or nothing situation. Either our equations are wrong about everything (including US and British weapons) or this one bit of data, from one of three sources, is incorrect. Any serious student of history should KNOW that bogus data from "official" sources is not uncommon at all. So why is it so hard to believe this when all other things are factored in?

If the German test data as a whole is wrong, then so is the American and British data for the same weapons. Worse, if the German test data is wrong then the American and British test data on their own weapons must be wrong too. Why? Because we came up with equations that produce all of these results accurately, and therefore if you chuck out one batch you must chuck them ALL OUT.

Contrast that with our position...

One particular set of data for the 88L/71, which is in conflict with two similar sets of data, runs counter to all the other data available for German, US, and British guns when crunched through our equations. Through scientifically sound equations we can reproduce all of these results EXCEPT for the 88L/71 data that you are claiming is the correct one out of the three conflicting data sets. However, one set of data from Aberdeen supports our numbers, derrived from the same equations that came up with all the other correct numbers. Therefore, we have at most a disagreement with two sets of data for one gun. You would have to call into question all but one set of data for one gun from three different nations for your argument to be valid.

I hope others can see how silly this debate is. Ours is sound and watertight if you drop out two out of the three 88L/71 data sets presented here. Since only ONE can be correct, this is not unreasonable to do. The opposing case calls into question ALL OTHER BALLISTICS DATA FROM THREE MAJOR NATIONS in order to support one out of three sets of data for a single gun. And what is our case based on? Perponderance of evidence and independently derrived scientific results. Your case? Simple faith that the one out of three you have is correct and that it somehow can be taken out of context of the whole, or that everything else is all wrong.

<BLOCKQUOTE>quote:</font><HR>Another thing ppl need to realise by questioning this we are not attaking Charles or Steve or CM, we are looking for the truth. <HR></BLOCKQUOTE>

Perhaps this is what you are after. As for Helge and Paul, I don't think this is totally accurate.

Steve

[The DesertFox]

Charles,

You have to normalize the data. What you did is...ummm...certainly not normalizing. You need to read the reports to be able to normalizing the data. Of course that will take time.

However to make it short. You are right the WO 219 LF test and the Bovington test do significantly in huge areas differ from the WaPrüf reports. Now you only have to find out WHY and you will be close to solving a miracle.

You know what ? What do you think WHY german pentration tests results have been established as a standard when you want to discuss this matter ? There is a reason.

Nevertheless I am not going to waste my time trying to hint you that something with your formula might be the reason for the obvious non ability to reproduce test data.

And you are right if you assume that in this case my trust in established test data (and it isn´t that the Jentz figures are the only ones) is much greater than in artifical mathematical produced figures.

You have your point of view, and others have theirs. Only thing you really should not do is publishing the penetration figures produced by your mathematical solution and question established test data with it. You will experience some surprises if you do that.

Once again I want to point out one thing clear. This is no gamekiller for me. The positive aspects of the game hugely predominates this issue. Although Steve seems to think something else

Case closed for me.

Helge

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>And you are right if you assume that in this case my trust in established test data (and it isn´t that the Jentz figures are the only ones) is much greater than in artifical mathematical produced figures.<HR></BLOCKQUOTE>

I'll take logic and science, supported by the majority of the data, over blind faith and question dodging any day. Our position makes sense because the only thing that it suggests is that a set of data for ONE gun from ONE nation is flawed, while yours suggests that ALL BUT ONE set of data for ALL BUT ONE gun from ALL NATIONS is incorrect.

And what is with all the "hinting"? If you have any rational, scientific reasoning that our equations are wrong, why don't you just present it?

Sorry, but we can not let a hollow and flawed challenge to the entire treatment of ballistics in CM just sit around to confuse people. If you have a real case to present, and one that involves challenging ours with something more than blind faith and question dodging, you have yet to present it. As it stands we have science and logic, as well as the data of three nations, on our side. You have only blind faith and slective reasoning to support your claim. I think all but one or two others can see that very clearly now. And therefore case closed.

Steve

[This message has been edited by Big Time Software (edited 08-24-2000).]

[Simon Fox]

<BLOCKQUOTE>quote:</font><HR>The point of contention here is: Charles public statement that The German Wa

Pruf Waffamt: wartime data used by Jentz concerning penetration results obtained in LF tests of KwK.43 annunition is flawed. All signifigant data of these tests has been supplied as well as the outcome.<HR></BLOCKQUOTE>

Though I hesitate to speak for him this is not my impression of what he is saying. My impression is that he is saying they are inconsistent with other data and therefore "suspect" in the absence of other evidence to the contrary. Which is not precisely the same meaning as "flawed".

<BLOCKQUOTE>quote:</font><HR>Their is a bigger issue here apperently no one sees but me, if the 8.8cm data is flawed then ALL German ammunition test results are flawed as the same criteria was used for all German ammunition.<HR></BLOCKQUOTE>

Whoa, well there is a good reason no one else sees it, it aint there. I fail to understand how you can come to such a bizarre conclusion based on this discussion. Sheesh, some guy was sacked for falsifying a research paper the other day....well there goes the entire years research output for the US in that field

<BLOCKQUOTE>quote:</font><HR>Simon, you are incorrect in that primary source material has not ben cited. <HR></BLOCKQUOTE>

Well strictly speaking I am not. Jentz and Hogg are not primary source material even if they worked from it. My point is that properly they should be cited as 'blah blah data blah' from 'such and such wartime document' as cited/reviewed by Jentz/Hogg.

<BLOCKQUOTE>quote:</font><HR>It seems logical to me that if I make a public claim that is contrary to primary

source material or a preponderance of documentation; that its up to me to provide empiracal evidence to support that claim.<HR></BLOCKQUOTE>

Well this is a gross oversimplification of the circumstances as you should know since what is in fact occurring is a disagreement between primary source materials in addition to the mathematical model. It can hardly be characterised as 'the model' disagreeing with 'real' world test results but rather one set of real world test results of possible questionable integrity which in turn do not agree with other real world results.

From where did Hogg source his data?

The fact is that everyone should be less concerned with defending one (or two) sets of test data vs another, and more with the intellectual question of how these discrepancies could come about, whether through methodology or human intervention at the data analysis stage. Then rather than just blindly support one set we could have some sort of rational discussion about it. Generally it is the body of evidence both theoretical and experimental that counts not specific parts.

[Vanir]

This has been one of the most interesting threads I've read here in a while. Very informative and entertaining.

<BLOCKQUOTE>quote:</font><HR>Originally posted by The DesertFox:

However to make it short. You are right the WO 219 LF test and the Bovington test do significantly in huge areas differ from the WaPrüf reports. Now you only have to find out WHY and you will be close to solving a miracle.<HR></BLOCKQUOTE>

You and Paul and John are the ones suggesting that the established test data is more reliable than BTS's physics models. Therefore, it is your responsibility, not BTS's, to explain the fact that the test data disagrees with itself.

<BLOCKQUOTE>quote:</font><HR>Nevertheless I am not going to waste my time trying to hint you that something with your formula might be the reason for the obvious non ability to reproduce test data.<HR></BLOCKQUOTE>

And which set of data is it that they are failing to reproduce? This is important since they are not the same. It is puzzeling that you can admit that the test data is not in agreement in one paragraph and in the next write something that would suggest it is in agreement. It's almost as if you don't consider the differing test data to be a big problem. It's a huge problem that undermines your whole arguement.

<BLOCKQUOTE>quote:</font><HR>You have your point of view, and others have theirs. Only thing you really should not do is publishing the penetration figures produced by your mathematical solution and question established test data with it. You will experience some surprises if you do that.<HR></BLOCKQUOTE>

Wrong. Charles and Steve have stated numerous times in this thread that the results derived from their physics model match very closely the test data for for all weapons other that 88L/71, including British and American. There would be no surprises at all. Once again, this has been said many times in this thread, but you seem determined to ignore it or simply not believe it.

If this discussion is to continue there are 3 questions that must be answered. No further progress is possible until they are.

1. Why do the various test results presented here as facts disagree with one another? Logic dictates they can't all be right. This has been asked many times by Charles and Steve and never answered.

2. Related to #1. Which one? If BTS is to change the modeling of the 88L/71 penetration to match established test data, they have to know which set of data to follow. You can't present a bunch of data that is in disagreement with itself and say "this is the way it should be". This has also been asked before.

3. If there is something inherently flawed with BTS's physics model, as seems to have been "hinted", why does it only manefest itself in the 88L/71? Steve and Charles have never claimed perfection, but logic (that word again ) suggests that any serious flaw in their models would result in data which rarely if ever matched test results. The only other explanation is that there is something unique about the 88L/71 that throws the BTS model out of whack. But what could that be? Asked many times and never answered.

Once again, great discussion to all. This BBS and CM itself are the best $50 I've spent in a while.

[This message has been edited by Vanir (edited 08-24-2000).]

[:USERNAME:]

I admit I havent read through this whole thread but saw something where 75mm and 88mm weapons are compared. The german 75mm weapons all fired the same AP rounds. Was the same true for 88mmL56 and 88mmL71?

By comparing 75mmL24, 75mmL48 and 75mmL70 you can get a good comparison.

Lewis

[Guest rune]

I am not the master of what you are discussing...not even close...but the points that stick out for me, are:

1. BTS' formula works for various countries and various weapons. There are 1 or 2 excepetion the main one being discussed the the 88L71.

2. The formula MATCHES post war data from two very impressive testing ranges. Bovington and Aberdeen. Anyone going to say that both these institutions got it wrong?

3. The Arguement is the German War testing numbers do NOT match. Other have used these numbers. Since we do NOT know how the German's tested...AND a rumored document states the numbers could be slanted, why would I support those numbers?

4. Did all the tests match? No. If a median of all the tests were used [which itself could be flawed, we would have to know where each quoted data from] Is ti that much of a difference? Is it enough of a difference to try to update the formula?

5. Newer formulas now exist. OK, has anyone used the newer formula on the 88? If it doesn't match the results at Bovington and Aberdeen, then are these two established centers incorrect? Personally, since I am in contact with people from there, I will tend to believe their figures first.

6. Last...I think both sides made good points. However, people are acting like Steve and Charles are purposely trashing research. They aren't...and have made their cases well. Do you think they pruposely made the 88 different? Or maybe, just maybe, they did the best they could with varied data. 5 sources, 5 sets of data. They are NOT using a table, but a FORMULA. Let's see YOUR formula that meets all the data of all the weapons AND fits the 88 data.

Viewpoint of a non-grog who thinks this is getting carried away.

Rune

[Paul Lakowski]

People stop using the Ordnance board report as good science and physics...NO ONE USES THIS FORUMLA ANY MORE. Ive never seen any reference to it in the 'abstacts' of the papers that I look at.

This is a 50 year old formula , which already makes it suspect, cause no formula survives more than 5 -10 years in the engineering journals before its ripped to pieces and rebuilt to better explain the events. The inconsistancies we've stated above would be more than enough to send the researchers back to the drawing board.

None of us are ballistic researchers , so we have to go to the sources. I'll start digging throught the mountains of journal to see what I can find , I suggest you all go do the same and then may be we'll all get some rest and somewhere.

I'sorry but the burden of proof has always remianed with BTS.If I go to some interested third party and say that Jentz , Hogg and others consistantly report the same data for a round of ammo , while this CM game claims -to the death I might add- another completely different value .... who do you think there going to believe?

[PzKpfw 1]

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

ARGH!! Not true!! What about the Aberdeen data?!? What about scientifically derrived results that match litterally dozens of other data sets without further exception?!? How can you just dismiss this out of hand and yet offer NOTHING on your side other than "I have chosen this one set of data and, based on nothing other than personal prefference, know in my heart that it is correct and you are wrong"

<HR></BLOCKQUOTE>

Here is the 'evidence' supplied by BTS it is all from Tom Jentz's books useing Wa Pruf data:

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

Name 75 L/48 75 L/70 Difference

Muzzle Velocity (m/sec) 740 925 +25%

100m penetration 99mm 138 +39%

500m 91 124 +36%

1000m 81 111 +37%

1500m 72 99 +38%

2000m 63 88 +40

Note how the 75/70 has a velocity 25% greater than the 75/48, and penetration about 38% greater. Now let's compare the two 88mm guns.

Name 88 L/56 88 L/71 Difference

Muzzle Velocity (m/sec) 773 1000 +29%

100m penetration 120mm 202 +68%

500m 110 185 +68%

1000m 100 165 +65%

1500m 91 148 +63%

How do I reach this conclusion? The simple physics behind it. Combat Mission does not use "penetration tables" or charts to determine armor penetration. Instead it uses the mathematical equations described in

"Penetration of Armour Plate" originally by (British) Ordnance Board Subcommittee of the Armour Piercing Projectile Committee (reproduced by U.S. Dept. of Commerce National Technical Information Service

#PB91127506).

<HR></BLOCKQUOTE>

No where in this discussion has BTS supplied 1 scientific formula Ie, the type Paul used would suffice detailing how the KwK.43 8.8cm ammunition penetration was derived and found flawed.

Again I i'm accused of 'my' numbers are wrong or i'm useing my 'personel preference' etc; these are not my numbers Nor am I championing them, you opened this can of worms,I merely want it quantified.

I am also well aware of other published penetration data, I have tried to narrow the feild down to concentrate on the primary test data, and apperently that is not acceptable, because it rules out useing Aberdeen, Bovington etc, after war equasions which are impoirtant to BTS's claim.

The importance of the German data is it supercrdes all other data provided here as it is the original results, You point out Aberdeen suports your formula results, yet I could say Wa Pruf & Waffamt results (notice I said could) supports the 8.8cm data used by Jentz, and I'm empiracly wrong.

What was the criteria for Aberdeen's test results plate BHN etc? and why is Aberdeen more accurate concerning the 8.8cm ammunition performance then, the Germans or Bovington etc,? as you said they all have varying numbers.

& It does effect all German tests even if only in credibility; you cant have it selectivley effect what you wish; even if your numbers match; the majority of data because the same plate etc; was used to derive all German test data, which is the base results that EVERYONE else used after the war(inc Bovington) to do their own mathmatical computations concerning the German test result data & came up with their own numbers, Aberdeen did the same, all these test results are derived from after war mathmatical formula computation based on the original German Wa pruf data.

Their is no attempt to dodge any issue (I know some appear to wish I would) the issue here is a simple quest for knowledge that can easily be settled with BTS provideing their "scientifically derrived formula" equasions concerning their 8.8cm ammunition formula so it can be analysed and a final conclusion based on it. And if stands up; pats on the back, kudo's & you can proudly say 'told you so & your can of worms can be closed.

Simon: I'll stand by my posts. Jentz used Wa Pruf data which is primary source data.

if you want the exact titles etc; contact Tom Jentz, most of the stuff is located on microfilm in Washington, and available to the public, well whats unclassified is.

Regards, John Waters

-----------

"Go for the eyes Boo!! go for the eyes!!".

[This message has been edited by PzKpfw 1 (edited 08-24-2000).]

[PzKpfw 1]

Bah dbl post, sorry.

[This message has been edited by PzKpfw 1 (edited 08-24-2000).]