Miles Krogfus Article on Russian Penetration Data

[rexford]

The following response to a post by Jason C on the regular CMBB forum brings out some of the great discoveries and conclusions that follow from Miles Krogfus's article in the May-Aug. issue of AFV News , which just came out:

Jason C started off the thread by saying: " I thought some might find interesting the following analysis I made of random side angles and their effects on conclusions drawn from tactical anecdotes about penetration possibilities.

The anecdote that got me thinking about the problem was about a couple of Tigers that found themselves in the midst of a formation of T-34/76s and were hit around 20 times without being penetrated. Some wanted to conclude from this that the 80mm flat side armor of the Tiger I was not penetrable by the 76mm at any range.

Over at the Russian battlefield site, meanwhile, they list the initial penetration of the BR-350B (capped) round as 84mm at 500m. Of course we do not know whether the capped rounds were available in the engagement in question. But assume it was."

Miles Krogfus' article on Russian penetration figures is now available in the May-Aug. issue of AFV News, and is a "must have" for armor penetration fiends.

According to Miles, Russian penetration data for 76.2mm BR-350B ammo is against high hardness armor, which I believe to be face-hardened, and is further reduced in general applicability by one other fact that Miles brings out in his article.

Miles' article indicates that the Russians produced two qualities of 76.2mm APBC ammo, the general type being mass produced in quantity and a special high potency round which was available but in smaller lots.

The published penetration data on the Russian Battlefield site agrees fairly well with the predicted performance of the high potency Russian 76.2mm APBC, and would not apply to the typical ammo used by that gun.

One cannot apply Russian Battlefield penetration figures directly to Tiger armor cause the estimates are against an entirely different type of armor.

The existence of two BR-350B rounds with differing quality may also explain why 76.2mm hits defeated Tiger II side armor in one test at 300m, and failed miserably in another.

===========================================

Starting from U.S. tests with 122mm APBC vs rolled medium hardness homogeneous armor and working to an estimate for BR-350B average ammo at 500m with 662 m/s muzzle velocity, we obtained 72mm penetration at 500m against homogeneous armor plate for BR-350B fired from 76.2mm.

So at 500m it is doubtful that T34/76's or 76.2mm field guns firing typical BR-350B will defeat Tiger homogeneous side armor with medium hardness. We estimate 77mm penetration against medium hardness homogeneous armor for 76.2mm typical ammo at 250m.

The souped up BR-350B can penetrate Tiger side armor at 500m with a lucky roll and little side angle.

Miles' article indicates that Russian tests against Tiger showed that 76.2mm penetrations could not be obtained at reasonable ranges. However, based on my calculations penetration estimates for the relatively rare 76.2mm solid shot AP indicate that that round could defeat 82mm at a good range.

Get Miles' article and it will shed some real light on what those Russian penetration figures mean. There is much more in the article than the above discussion addresses.

[JasonC]

"why 76.2mm hits defeated Tiger ***II*** side armor in one test at 300m, and failed miserably in another."

Tiger II side armor is sloped. Tiger I side armor is not.

The test evidence is that sometimes BR-350B defeated 80mm at 25-30 degrees slope at 300m. CMBB performance is that it fails pretty much uniformly against 80mm without slope even at 100m.

On its face, that is evidence of undermodeled Russian 76mm ammo quality and/or overmodeled German armor quality, not of the reverse.

[ April 21, 2003, 07:49 PM: Message edited by: JasonC ]

[PzKpfw 1]

Originally posted by JasonC:

On its face, that is evidence of undermodeled Russian 76mm ammo quality and/or overmodeled German armor quality, not of the reverse.

Truth is we don't know which one it is, & neither did Soviet wartime fireing trials with the 76mm Ie, excerpts from Instruction on fighting German tank T-VI signed by Artillery Marshal Voronov, 20 April 1943:

The front part of T-Vi is reliably penetrated by anti-armor shells of 45-mm guns model 1942 and 57-mm and 76-mm of all models from distances 100-700 m, by armor-piercing shells of 122-mm guns model 1931, 152-mm gun-howitzers model 1937 from 700-1000 m.

Sides, rear part and turret additionally to that are penetrated by subcaliber shells of 45-mm gun from 200-500 m, by armor-piercing shells of 57-mm AT guns, 76-mm and 85-mm antiaircraft guns from 1000 m.

76-mm gun model 1942:

at suspension, turret and gun;

from 700 m at sides, rear, turret - by sub-caliber shells, from 100 m at front part.

76-mm AA gun:

from 500 m at sides, rear and turret - by armor-piercing shells; from 700 m at the front part by sub-caliber part.

Then we have, another Soviet live fire report on the Tiger E that totaly contradicts the April report Ie,

In spite of the fact, that this captured artillery system reliably penetrates the armor plates of 80mm and 85mm thickness from the testbench at the virtual distance of 600m, during the firing at Tiger tank by

two pieces with 30 AP rounds each from a distance of 600-500m no full penetrations of side armor were obtained

Conclusion: Tiger tank currently is invulnerable to attack by conventional AP shell from all known models of medium calibre AT artillery.

Signed

Saenko, Melnikov, Satel

Verified: Ustinov, Voronov

September 11, 1943

From other parts of the report, there was not 1 single penetration of the Tiger E side armor @ 500 - 600m from any of the following guns: ZIS-3, F-22USV, F-34, PaK-36®, 57mm M1 gun, 85mm obr.1941 AT gun.

The only 2 Soviet guns that defeated the Tiger E 80mm side armor @ 500-600m were the 57mm gun (ZIS-2) and 85mm obr.1941 AT gun & only by useing improved rounds.

Below are excerpt from an 1st Baltic Front No.02119 dated May 22, 1944. Concerning fighting German heavy tanks (PzKpfw V, PzKpfw VI):

1. Open the fire only at the close, point blank ranges allowing effective destruction of the German tanks.

5. The officers guilty of the premature opening the fire are to severely punished.

Various other Soviet orders perscribes the best method of killing Tigers was with Katusha's. It's also interesting Soviet M4A2 Sherman tankers reported the 75mm M72 round could reliably defeat the Tiger E side hull & turret armor.

Regards, John Waters

[ April 22, 2003, 01:35 AM: Message edited by: PzKpfw 1 ]

[rexford]

John Waters said:

"It's also interesting Soviet M4A2 Sherman tankers reported the 75mm M72 round could reliably defeat the Tiger E side hull & turret armor."

75mm M72 AP can penetrate 93mm of homogeneous armor at 500m, and over 100mm at close range.

Russian Battlefield penetration figures are not against armor type carried by Tiger, so cannot be compared. That is what Miles' article indicates.

Following are my latest revised penetration figures for 76.2mm firing APBC (BR-350B):

Typical Round

84mm at 0m

80mm at 100m

77mm at 250m

72mm at 500m

67mm at 750m

62mm at 1000m

Special Super Round for BR-350B (available late 1943 according to Krogfus article):

Increase above figures by 10%

The ranges posted by John Waters suggest that 76.2mm BR-350A could not penetrate Tiger side at any range, where BR-350A might be primary round during April 1943 trials against Tiger.

BR-350A would penetrate about 8.4% less than BR-350B according to data in Miles' article, so reduce typical pen figures in table above for BR-350A and obtain 750m pen range for 76.2mm BR-350A against 62mm armor on Tiger lower side.

[rexford]

Following are my latest revised penetration figures for 76.2mm firing APBC (BR-350B):

Typical Round BR-350B

84mm at 0m homogeneous, 86mm face-hard

80mm at 100m, 84mm face-hard

77mm at 250m, 81mm face-hard

72mm at 500m, 77mm face-hard

67mm at 750m, 72mm face-hard

62mm at 1000m, 67mm face-hard

76.2mm APBC BR-350B penetrates 80mm at 9 degrees slope (PzKpfw IVH driver plate) at just under 250m if armor is face-hardened, based on my interpretation of Miles' article.

Special Super Round for BR-350B (available late 1943 according to Krogfus article):

Increase above figures by 10%

Above estimates based on U.S. tests with 122mm against rolled homogeneous armor, which were converted to 76.2mm APBC effectiveness at 662 m/s muzzle velocity. Face-hardened figures from Miles' article, which presents equation and constants to be used.

The ranges posted by John Waters on CMBB forum suggest that 76.2mm BR-350A could not penetrate Tiger side at any range, where BR-350A might be primary round during April 1943 trials against Tiger.

BR-350A would penetrate about 8.4% less than BR-350B according to data in Miles' article, so reduce typical pen figures in table above for BR-350A and obtain 750m pen range for 76.2mm BR-350A against 62mm armor on Tiger lower side.

[JasonC]

The September report says the PAK 40 with German ammo could not penetrate the Tiger I side, flat, at 500m. Does anybody here actually believe that? It is horsefeathers, on its face. The round has 50% more penetration ability than it needs. That report is not credible.

Russian numbers for the US M3 are up to 10% lower than US numbers for the US M3. That is not ammo differences. It is obviously different armor tested or different penetration criteria (e.g. 75% through).

The Russian 76 and the US M3 have nearly the same energies. If you take Russian numbers for all of them, the BR-350B marginally outperforms US M3 while BR-350A marginally underperforms it.

Specifically, take IP+CP/2 as the 50% penetration value to compare to single entry figures for the M3. At 500 and 1000 vs. 30 slope, the Russians give 66mm and 60mm to the M3. The Russian 76 has 6% higher muzzle energy (2.75 mJ vs. 2.6 mJ). Russian battlefield numbers (as above) for the BR-350B come to 69 and 63, 5% higher than their own figures for the M3. Their figures for BR-350A work out to 64 and 57, or 3-5% lower. There is every indication the round difference, A vs. B, straddles the performance of the US 75.

The tactical data against other tank types essentially agrees. Grants were killing 50 and 30+30 panzers at 1200 to 1400m, by German AARs. Russians were standing off at 1000 to 1200m in the same period.

Both rounds are rated by CM as marginally better than 25 pdr AP, which was reliably penetrating the same thicknesses at 1000m. There is no tactical evidence the Russian 76 was dramatically weaker than either US 75 or Brit 25 pdr. The tactical evidence suggests its performance is bracketed by the two.

Russian battlefield says as the Germans fielded superior armor in the course of 1943, their 76s needed ranges of 500m. That fits their own numbers against 80mm fronts. Their ATG doctrine for 76s agrees.

Before you conclude a number must be wrong because it is a different type of armor, show that the number is wrong in the outcomes it predicts.

72 flat at 500 is 11% lower than CMBBs present numbers for the T-34, 13% lower than its present numbers for the US 75, and only 9% higher than its present number for the 2 pdr. It presents the Russian 76 with 2.75 million Joules of muzzle energy as midway between, in fact slightly closer to the performance of a 2 pdr, with less than 1 million, and a 2.6 million Joule US 75.

Nobody has explained how we have a clear test result saying BR-350B penetrated a Tiger II side at 300m, when supposedly it can't penetrate an unsloped Tiger I side at any range. In CMBB today, it can't penetrate a Pz III from the front at 500m. We are told it must be revised still further downward. It is absurd.

If instead you believe the Russian battlefield numbers, you've got 82 IP - which is supposed to be 20% penetration chance - vs 30 slope at 300m. The implied chance against the Tiger II side at that range is around 25-30%. No difficulty explaining the empirical observation. 72 flat at 500 can't.

The Russian battlefield numbers - and present CMBB numbers printed in the range windows, as opposed to the "shell broke up" performance one actually sees instead - are right, or darn close to it. They agree with all tactical evidence.

The only first hand report on the other side says a PAK 40 with German ammo capable of penetrating 125-130mm of armor flat failed against 80mm flat at 500m. If that report said pigs have wings it would be equally credible. It was probably a lobbying attempt to get 85mm guns.

The Russian 76mm was not a 2 pdr. Attempts to transform it into one to save uber Panzer dreams would be the silliest, biased revisionism.

If 72mm is meant to be for 30 degrees it would be believable. The Russian battlefield numbers for 500m at 30 degrees make 69mm the mid point of IP and CP, or expected 50% penetration value. But not for flat.

As for 60mm Tiger sides, that plate is simply not exposed. It is covered practically entirely by the running gear. For all intents and purposes, the Tiger is fully protected by at least 80mm of armor. You can't conclude from failures to knock them out with side hits that the ammo couldn't penetrate 60mm, because no 60mm plate would actually be struck (without deflecting from road wheels, thus facing greater overall thickness, etc).

I now leave the faithful to their labors.

[ April 22, 2003, 03:13 AM: Message edited by: JasonC ]

[kipanderson]

Rexford, hi,

Very interesting stuff.

Correct me if I am wrong, but you are saying that until late 43 a slight reduction in penetration against Homogenous armour is the order of the day. However, and this is the important bit for me, against Face Hardened armour we are talking a net increase over the current figures in CMBB?

Currently, in CMBB a Soviet APBC round that will penetrate 80mm of Homogenous armour will only penetrate around 70mm of Face Hardened armour. You are saying that the new figures would mean that a Soviet APBC round that will penetrate 80mm of Homogeneous armour, will in fact penetrate slightly more Face Hardened armour at around 84mm?

Have I understood what you are saying?

If I have this does fit with a report I read in the archives of the Tank Museum in Bovington. It indicated that the in the view of the British the Soviet 76.2mm APBC rounds would have “some” anti-Face Hardened affect along the lines of Western APCBC rounds.

In fact I have previously tried to persuade Charles that the Soviet rounds should be given “some” credit for anti-Face Hardened abilities. BTW. The British view was based on 42 APBC rounds that shipped with the now famous T34/42 and KV1 that the Soviet sent to the British in 42.

Very interesting stuff.

All the best,

Kip.

[PzKpfw 1]

Originally posted by JasonC:

The September report says the PAK 40 with German ammo could not penetrate the Tiger I side, flat, at 500m. Does anybody here actually believe that? It is horsefeathers, on its face. The round has 50% more penetration ability than it needs. That report is not credible.

Jason why would the Soviets falsify the report? & why would Marshal Voronov sign off on a false report?. What did they have to gain by falsifying the report?, you sugest it was a move to get the 85mm in service, yet the S-53 85mm gun was already completeing its fireing trials during Nov, on the 2 obiekt 135, prototypes & and would be accepted into service as the T-34-85 on Dec 15 1943.

In stead of claiming the report was not credible etc, you would think ppl would wonder why 7.5cm PzGr.39 failed, vs the Tiger E armor, was it due, to a bad batch of PzGr.39?, was it even PzGr.39 to begin with? or was it Soviet manufactured ammo for the tests?, etc.

Lets look at 75 L/48, penetration in German wartime tests was 91mm @ 500m @ 30^ in Soviet tests the PaK 40 penetrated 85mm @ 500m @ 30^.

British tests in North Africa found the 80mm Tiger E side armor resisted as if it was actualy 82mm of British plate. In US live fire tests vs the Tiger E, the 80m side srmor resisted as if, it was of a greater effective thickness, Ie, in the tests with 90mm APCBC their are instances where the 80mm plate resisted 90mm APCBC attack as if, it was actualy 91mm thickness.

Then theirs the fact that not a single Soviet gun, defeated the Tiger E 80mm armor @ 500 - 600m, @ 0/30^ in the November report, all Soviet guns failed to penetrate Tiger E side armor even @ 0^ @ 100m.

Penetrations & partial penetrations were obtained on the 80mm side armor by 57mm obr.1941 gun (ZIS-2) and 85mm obr.1941 AT gun useing APS/HVAP at an maximum range of 500m @ 0^ degrees. The Tiger E front armor was impervious to all Soviet guns in the tests @ all ranges.

Quite a difrence from the April report alleged penetration results. Another Soviet report I have refrenced before on the misflavored thread concerning the Panther LF tests, on page 2, reads:

Overall if we are talking about Panthers, they are quite good, even though there are some problems with starting the engine and its protection. Unlike that of Tiger, side armor is not invincible for 76-mm anti-tank shells.

If the 76mm could defeat the Tiger E 80mm side turret/hull armor @ 500m as you sugest, not one Soviet wartime LF test vs Tiger E side hull/turet 80mm armor supports penetration by 76.2mm cannon or tank gun, after the April pamplet, on combatting the Tiger E.

Specifically, take IP+CP/2 as the 50% penetration value to compare to single entry figures for the M3. At 500 and 1000 vs. 30 slope, the Russians give 66mm and 60mm to the M3. The Russian 76 has 6% higher muzzle energy (2.75 mJ vs. 2.6 mJ). Russian battlefield numbers (as above) for the BR-350B come to 69 and 63, 5% higher than their own figures for the M3. Their figures for BR-350A work out to 64 and 57, or 3-5% lower. There is every indication the round difference, A vs. B, straddles the performance of the US 75.

Exactly what 75mm round are you compareing Jason? BR-350A/B vs 75mm M61 or M72?.

Soviet results, 76mm Fireing BR-350A @ 30^:

300m - 71mm

500m - 67mm

1000m - 60mm

1500m - 54mm

German Wartime live fire test results with 76mm Soviet guns :

76.2mm L/30.5 MV: 575m/s:

100m - 72mm

500m - 66mm

1000m - 58mm

1500m - 51mm

76.2mm L/41.5 MV: 625m/s:

100m - 82mm

500m - 75mm

1000m - 67mm

1500m - 60mm

IIRC the above results were with German produced 76mm ammo.

Then we have the British LF tests with the M3 Ie,

shoot 1 with 75mm A.P.C.B.C. M61 Shot from a new M3 gun in a Sherman:

Against 82mm side superstructure, fireing was opened up at 30 degrees. This gave a scoop with a very slight bulge at the back.

The angle was progressively reduced until at 16.5 degrees a complete penetration was obtained. At 18.5 degrees one round was fired which failed to penetrate.

Thus the W/R limit of this plate at 17.5 degrees angle of impact was about 2020 ft/sec. Onthe outside of the plate all displacedmetal sheared away, leaving avery jagged and irregular entry hole for shot. The metal displaced from the back by overmatching round at 16.5 degrees was 11 by 6 inches.

British Live fire testing vs Tiger E Fgst.Nr.250570 using M61 APBC from British report: A.T.No.252 Part II.Dated 16 to 22 March 1945:

75mm APCBC (M61) @ 20^:

Superstructure and Turret sides 82mm . Attack against the superstructure and turret sides at full service charge failed to defeat them.

There is no tactical evidence the Russian 76 was dramatically weaker than either US 75 or Brit 25 pdr. The tactical evidence suggests its performance is bracketed by the two.

Exeept that the US 75mm rounds consistantly outperformed Soviet BR-350 ammunition. Soviet tankers reported the M72 round could reliably defeat the Tiger E side hull/turret, wheras the 76mm on the T-34-76 could not defeat the Tiger E 80mm side armor, at any range.

Nobody has explained how we have a clear test result saying BR-350B penetrated a Tiger II side at 300m, when supposedly it can't penetrate an unsloped Tiger I side at any range.

Interesting in the live fire tests vs the Tiger II in 1945 @ Kubinka, not 1 Soviet 76mm gun penetrated the Tiger II side armor, Ie,:

8. The tank's hull and turret side plates were penetrated by armor-piercing projectiles from the domestic 85 mm and American 76 mm guns at ranges of 800-2000 metres.

9. The tank's hull and turret side plates were not penetrated by armor-piercing projectiles from the domestic 76 mm guns (ZIS-3 and F-34).

10. American 76 mm armor-piercing projectiles penetrated the "Tiger-B" tank's side plates at ranges 1.5 to 2 times greater the domestic 85 mm armor-piercing projectiles.

Here again in another Soviet LF report we see the failure of the 76.2mm to defeat 80mm armor, whereas, the US 76mm defeated the armor out to 2000m. The question is IMHO ammo quality Ie, US 75mm & 76mm consistantly outperformed the Soviet 78.2mm & 85mm ammunition. Why? on paper bot are very well matched Ie,

Sherman 75mm Fireing M72 @ 30^

457m - 76mm

914m - 63mm

1371m - 51mm

76mm F-34 Fireing BR-350A @ 30^ BR-350P sub-calibre in ( ) @ 30^

500m - 67 (75mm)

1000m - 60mm (47mm)

1500m - 54mm

85mm Zis-S-53 firing BR-365 @ 30^ BR-365P sub-calibre in ( )'s @ 30^

500m - 91mm (116mm)

1000m - 83mm (84mm)

1500m - 76mm

Sherman 76mm fireing M79, M93 APCR-T in ( )'s @ 30^

457m - 109mm (157mm)

914m - 92mm (135mm)

1371m - 76mm (116mm)

Regards, John Waters

[ April 22, 2003, 03:48 PM: Message edited by: PzKpfw 1 ]

[JasonC]

"why would the Soviets falsify the report?"

To impress upon the REMFs the need to get the 85s into the field ASAP, ramp them, and phase out the 76 as no longer adequate. Logistics and production types are always downplaying the need for new ordnance, wanting the front line to "make do" with what the supply system already has in the pipe.

"in German wartime tests was 91mm @ 500m @ 30^ in Soviet tests the PaK 40 penetrated 85mm @ 500m @ 30". Yes, because the Russians measured to 75% of projectile through, the Germans to 50%, and above all because *that's 30, not flat*.

Then you say I am suggesting the Tiger side was routinely defeated by 76mm at 500m. Did you read what I wrote about side angle and tactical conclusions? Absolutely flat shots are rare. Close range shots are rare. There is nothing routine about them. IP ratings are for 20% chance of penetration. I showed that the Russian battlefield numbers imply that 96% of shots from random locations within 1 km of a Tiger would bounce.

Which is consistent with some reports of failure and some reports of success. Always failing is not consistent with some reports of failure and some reports of success. BR-350B penetrated the side of a Tiger II at 300m, which is sloped. There is no way it was *impossible* for it to penetrate the same thickness, without the slope, even closer.

Then you quote numbers for the L30 instead of the L42. Then you quote numbers for the 1941 A instead of the B we are talking about. No, the German numbers are not for German produced ammo - they used the L51 and PAK 40 ammo, not the L42, which is specified in your figures. The numbers are higher because it is B not A, the L42 not the L30, and German measures of what counts as a "through" rather than Russian ones.

The 15-20 degree side angle or less needed is exactly the sort of thing the Russian data imply. 15 degrees is only a few percent of additional armor, while 30 is a lot of additional armor. It is when the side angle needs to be low like that that tactically you get ~96% protection, because it leaves only small lobes of vunerability near enough and flat enough.

When you then say "except the Russian 76 failed" where the M3 succeeded, you are begging the question. That is exactly what you are supposedly establishing, you can't assume it to prove the conclusion. There is no evidence the M3 was dramatically more effective than BR-350B against any other match up. Both were holing 50-60mm panzers at over 1 km, etc. The M3 has lower muzzle energy, though marginally so.

Meanwhile there are Tiger IIs with holes in them at greater overall angle to the same plate thickness, which does not at all fit the notion that Russian 76mm could not penetrate even with zero angle and at point blank. "Could not" is a harder condition than "did not once". One counterexample disproves "could not", and it has been presented to you.

As for "3 times the range" and US 76 vs. Russian 85, it is not magical untermenschen physik, it is just reality vs. theory. The US estimated its 76 could kill Tigers from the front, and Panthers through the turret, out to 1500-1800m. In practice they did not achieve that, because of shatter, and needed much closer ranges. The Russians just found something similar with their own 85. It underperformed *claims* made for the US 76, but so did the US 76.

I'm done arguing with you John, though if Rexford has any clarifications on kips question - and mine as to whether he means 72 flat - I'd be happy to hear it.

[ April 22, 2003, 06:55 PM: Message edited by: JasonC ]

[PzKpfw 1]

Originally posted by JasonC:

To impress upon the REMFs the need to get the 85s into the field ASAP, ramp them, and phase out the 76 as no longer adequate.

The 85mm was already on the T-34-85 prototpes & and was testing in November 1943. Also note in the tests the 85mm & 57mm ammunition did penetrate, while the 76mm ammunition did not, which in itself gives them an good reason on it's own to go to 85mm, without haveing to falsify documents etc.

Falsifying reports in Stalins USSR was much more dangerous, then say doing it, in the US or GB, in the same time period, Stalin tended to micromanage weapons details, just like Hitler did, as Aleksander Yakovlev and P.V. Dement'yev & others found to their dismay during WW2.

Which is consistent with some reports of failure and some reports of success. Always failing is not consistent with some reports of failure and some reports of success. BR-350B penetrated the side of a Tiger II at 300m, which is sloped.

Yet in the Feb 1945 tests not one 76mm round penetrated the Tiger II side armor, why is that Jason?. You refer to these 'tactical' reports, can you give us the refrence, author title, page # where we can read these 'tactical' accounts? ourselves. What is consistant is the 76mm failure in the live fire tests vs both the Tiger E & Tiger II side hull/turret armor.

Ie, the first Soviet LF trials vs the Tiger E were conducted on April 25 - 30th 1943 by NIIBT @ Kubinka, the T-34s F-34 76L/41 could not defeat the 80mm Tiger E side hull/turret armor at even 200m. The only Soviet gun that defeated the Tiger E armor was the 85mm M1939 52-K AA gun.

Then you quote numbers for the L30 instead of the L42. Then you quote numbers for the 1941 A instead of the B we are talking about.

Not sure what you are talking about here Jason, I presented pentration data for the T34-76's L-11 76L/30.5 & F-34 L/41.5 guns. As to the round, the BR-350A was the most common round in 1942, the BR-350B DOI was late 1942, early 1943. And that doesn't even cover when FL units recieved it, as their were large stocks of pre-existing BR-350A etc.

No, the German numbers are not for German produced ammo - they used the L51 and PAK 40 ammo, not the L42, which is specified in your figures. The numbers are higher because it is B not A, the L42 not the L30, and German measures of what counts as a "through" rather than Russian ones.

The

The gun results in my post were for the L/30.5 & L/41.5 T-34-76 tank guns. Also note the weight & MV of these rounds:

L/30:

Weight - 7.6kg

MV - 575m/s

L/41:

Weight - 7.6kg

MV - 625m/s.

Can you present an refrence that the Germans had access to BR-350B ammo in these tests?, Or that the Germans rebored the T-34s 76mm guns to accept German ammunition?.

The MV & round weights do not match published BR-350B ammo weight/MV for the T-34-76 or Zis-3 Ie, BR-350B MV was 680m/s, PAK 40 MV was 740m/s vs 625m/s in the German L/41.5 results.

The Germans rebored the field guns to use German ammo. They also produced PzGr.40 for them, the Soviets copied these rounds & made, for example the BR-350P round.

In past discussions on these test results on Tanker's it was the consensus that these tests were conducted with German produced 76.2mm ammo.

German penetration results with the F-22 with PzGr.39 @ 60^ PzGr.40 results in ( )'s :

100m - 108mm (152mm)

457m - 98mm (118mm)

915m - 88mm (92mm)

1372m - 79 (71mm)

1829m - 71mm (55mm)

Yes the Soviets used 75% critera, in that 75% of the projectile fragments had to be behind the plate after impact, as well as 2 other forms of penetration critera, Ie, IP, Initial Penetration which assumed 20% probability of penetration & CP, Certified Penetration which assumed 80% probability of penetration. We also do not know the quality of Soviet test plate BHN etc, as the tests never identify the plate other then to say it was high hardness homogenous, or just homogenous.

At the same time we can not dismiss the negative effects poor round construction had on their rounds performance. The Soviets themselves admit actual penetration, was signifcantly lower then then published wartime, data seen in the tables, due to to poor ammunition quality until almost 1944.

The Germans used 50% probability, my comparison was to show mms of armor pierced in Soviet tests, AFIK critera did not affect actual measured penetration in mms in LF tests.

What it did effect was their mathmatical estimations of performance. I Wish we had more data on German ammo quality as well as, it was slideing by 1944 as evident in assasments of PzGr.44 series ammunition quality. I don't have any 30^ pen data on the BR-350B only 60-90^ thats why I used 350A.

When you then say "except the Russian 76 failed" where the M3 succeeded, you are begging the question. That is exactly what you are supposedly establishing, you can't assume it to prove the conclusion.

I'm not assuming or establishing anything, Jason

I'm presenting facts supported by documents, from previously refenced Soviet reports.

Readers are free to draw their own conclusions from the reports vs heresay etc, as you did Ie, you feel Soviet reports are not credible etc, thats your opinion & your entitled to it.

These same reports also strongly sugest the 76mm gun could not defeat the Tiger E side 80mm armor. The reports from Soviet M4A2 75mm crews also sugest the US 75mm M72 round was more effective then the BR-350A or BR-350B round, vs the Tiger E's side armor.

If you have refrence grade material citations to the contrary, please post them so we can look at your data. The Tiger Es armor was more then capable of defeating Soviet ammunition or even German ammunition as evident in the November report, supported by both British & US live fire test results, concerning the Tiger E 80mm @ 0^ side hull/turret armor resisted as if it was actualy thicker then 80mm, Ie, it resisted 90mm APCBC as if it was 91mm of plate, in instances.

Meanwhile there are Tiger IIs with holes in them at greater overall angle to the same plate thickness, which does not at all fit the notion that Russian 76mm could not penetrate even with zero angle and at point blank. "Could not" is a harder condition than "did not once". One counterexample disproves "could not", and it has been presented to you.

Jason the November tests were done @ 100m @ 0^, I dont have data on PB tests, or even know if they did any. Show me in the Live fire tests I presented, here where the 76mm penetrated the Tiger E or Tiger II side armor. Present us with an actual Soviet test report(s) that shows the 76mm reliably penetrated of the Tiger side armor.

I can produce a few Soviet AA reports that imply the 76mm did defeat the Tiger II side armor, on one occasion, below 500m, it was claimed 76mm guns defeated an Tiger II's side turret @ 300-400m. But in 3 seprate Soviet LF tests conducted during the war, vs the Tiger E & Tiger II dont support the 76mm defeating the armor, nor do Soviet conclusions in the reports, as we have seen.

Does this empericly mean a 76mm round never penetrated a Tigers side armor, no it does not, what it does strongly imply, is 76mm penetration at any range would be extremely unlikely.

As for "3 times the range

Where did the report say 3 times the range?. I never mentioned any uber round theory etc, I said IMHO the Soviet rounds failures were more from poor quality then MV etc, which is supported by Soviet documentation to the same effect, US rounds of all types were of higher standard of quality compared to Soviet rounds.

I'm done arguing with you John, though if Rexford has any clarifications on kips question - and mine as to whether he means 72 flat - I'd be happy to hear it.

I hadn't realised we were "arguing" Jason. Am I and others, here to assume whenever anyone disagrees with you, it's considered argumentive rather then a discussion?. This is the second occasion we have disagreed on your posts content & you have refered to it as arguing. If in fact Jason I enjoy reading your posts, even if I disagree with them. What I don't care for is your continued lack of

suporting evidence Ie, refrences, to support your posts positions.

Ppl have repeatedly asked you for refrence citations, & never recieved an answer. Vauge refrences to an tactical manual sold on the BTS website that 'said this' does not qualify as a refrence.

I am merely presrenting data same as you, if my posts data conflicts with your posts content so what?, Its not about who's right or wrong its about shareing data, learning etc. We all can learn alot in a good debate, from each other & it would be pretty boreing if we all agreed on everything, would it not?.

Regards, John Waters

[ April 23, 2003, 10:22 AM: Message edited by: PzKpfw 1 ]

[rexford]

The 76.2mm BR-350B might have penetrated the Tiger II side armor in a test because they were using the special super round available late 1943, and the armor was inferior.

Russian APBC is flat nose and nose hardness is on order of 45-50 Rockwell C, American 75mm M72 AP has a very sharp point and is 54.5 Rockwell C Hardness nose.

75mm M72 will easily outpenetrate 76.2mm BR-350B against vertical homogeneous splate, while 76.2mm will close the gap against thinner armor at a bigger angle. Flat noses kick butt against angled homogeneous armor because the edges dig into the plate and counteract the ricochet forces.

[gorgias]

Amen Jason...u are great

[Panzer76]

JasonC, you talk alot about tactical references, AARs, Im curious as to where your references are, you please point us to it?