That´s my take, too.Avalancheon wrote: ↑02 Dec 2018 17:12They also tested the 45mm M-42 gun against the side, along with the 6 pounder gun. The 57mm ZiS-4 gun was tested against the front armor, and failed to make any penetrations.
tankarchives believed that it would have succeeded at a range closer than it was tested (I.E., 500 meters), but given the poor quality of Soviet ammo, this is highly unlikely. The 57mm shells would have shattered.
While differential shell quality (less so shell types, because none of the soviet wartime full calibre shells were shatter proof) can be a reason for variances, I really fail to see any disticnt incongruences.Avalancheon wrote: ↑02 Dec 2018 17:12Sorry, I simply can't agree with this assessment. The difference between the German and Soviet tests is too large to be ignored.critical mass wrote: ↑02 Dec 2018 16:01The 85mm can perforate the TIGER. I don´t see any inconcurrance between the WaPrüf- and soviet test data.
Even the 76mm ZiS-3 could easily penetrate the TIGER frontally or from the sides -provided it had decent quality APCBC-HE (76mm Pzgr.39 rot) instead of the soviet domestic APBC-shell. The TIGER´s manual danger ranges against 76mm are based upon this german projectile quality.
Why did the 30 degree obliquity in the Wa Pruef tests cause the 85mm guns range to be cut down so much against the Tigers? 1000 meters at 0 obliquity vs 200 to 300 meters at 30 degrees obliquity is a big difference.
Like I said to Peasant, I think it has to come down to different ammunition being used. Soviets were using special, shatter proof shells in their test. Whereas the Germans must have been using APBC shells, which tend to break up even at low obliquitys.
Range is irrelevant, In terms of terminal ballistics we are interested in velocity. This downrange velocity correlates with a range.
For WaPrüf perforation at 30° and at 200-300m, the downrange velocity would be 775m/s +-5m/s according to 1944 range tables for the 85mm gun.
ARTKOM´s 1000m range at 0° represents a terminal velocity of appox. 710m/s according to 1944 range tables for the 85mm gun.
Of course, I don´t know if they both used the same range estimates from range tables but we know that soviet range tables were captured by the germans and used in this sort of comparisons, so this presumption is at least possible in my opinion.
More difficult are different defintions of penetration and I can only assume that the failure mode is identic here (discing/pluggin likely with broken penetrator).
So You have for the 85mm gun:
100mm @0° = 710m/s
100mm @30° = 775m/s, very approximately
or a ratio of 1.0:1.09 in terms of velocity (0° and 30°, respectively)
According to german rules for perfectly undeformable, pointed, capped APCBC-HE, if the thickness at 30° is 1.00 then the thickness at 0° = 1.23times (30°). The apparent ratio here is significantly smaller than would be expected for perfect penetrators, even if added with velocity exponents to match increased thickness. This only leaves two conclusions:
A) the range difference for 0° and 30° is not unfeasable but entirely possible
B) projectile break up "flattens"or "caps" performance of the 85mm projectile compared to Pzgr39.
C) the projectile break up at 1000m is less pronounced than the break up pattern at 200-300m (as could be expected due to higher striking energy at close range)