7,5 cm Kwk/StuK/Pak 40 Firing Table Data

[critical mass]

its not from tank archives. Though when I reminded Peter S. that the original article of Y. Pasholok actually states that the 76mm AAA did not penetrate the 82mm side at 500m -as did the F-34- he selected Foto#29 from the report to "proove me wrong". Of course, neither did he mention that the report has two more impacts by this gun on 82mm sides at the same 500m, both of which only left dents and no holing (hit#2 & #3), nor did he reflected on plate edge effects of hit#1, which caused the cracking at the roof-side plate joint. Instead he states that the 76mm AAA penetrates the side from 500m, despite such a bold claim is not supported by the primary source in question. Because he also has access to the original report, one cannot but wonder why he deliberately need to make things up?

[critical mass]

The shell impacts look like from a blunt nosed shell typical of Russian 76mm AP.

One migth view it as such and it is a possibility. That beeing said, however, one shouldn´t forget that the diameter of dents are always >100mm, which indicates to me that the attacking projectile failed by upset (compression) and/or offset (bending) failures, at the very least. It´s possible and even very probable that they "mushroomed" out against the plate and left a >cal, ductile indentation in the plate. These sort of failures would leave similar looking dents for blunt headed and sharp headed projectiles, alike.
The nose shape of the uncapped projectile is of little importance if the projectile deforms or breaks up, which soviet domestic AP do against any discriminate target plate.

There was a wild number of differently looking 76mm AP-designs. I suppose, because the soviets didn´t yet standartize on a design. HHA armor plate was supposed* to be tested and later proofed by a special 76mm armor piercing projectile (drawing No. 2-03545), too. compare attachment, which looks very different to the BR-350A APBC bullet.
source:
https://t34inform.ru/

edit:
*that was before it turned out to be too brittle in 76mm impacts to be acceptable and the soviets-rather than improving the armor- just decided to delete the 76mm proof requirement, which left the plate to be tested vs domestic 45mm APBC and 37mm AP, both of which the pate defeated with flying colours.

[Mobius]

, which looks very different to the BR-350A APBC bullet.
source:
https://t34inform.ru/

It looks very much like a BR-350A bullet.

[critical mass]

You are correct Mobius.

It looks similar to Br-350A but dissimial to the Br-350 flat nosed APBC with large filler and the Br-350B flat mosed APBC with small filler mentioned previously in this thread.
Mea culpa.

[critical mass]

Soviet conclusions of the firing with 76mm AAA on TIGER side armor:

a) Бронебойный снаряд с дистанцин 500 метров не оте пробивает бортовую броню корпуса.
b) Металл Бронебойного снаряда имеет невысокие механические свойства.

translation:
a) Armor-piercing projectile fired from a distance of 500 meters does not penetrate the side armor of the hull.
b) The metal quality of the armor-piercing projectile has low mechanical properties.

Peter S. somehow made it up and in violation of the primary source claimed instead that "76mm penetrated the side armor" and "there is no evidence for poor metallurgic qualities of soviet domestic AP because it penetrates the Tiger side armor at elevated velocities".

As You might recognize, this is the exact opposite of the findings in the original prooving ground report. Further, the report is explicite in associating the failure to penetrate the TIGER side armor with 76mm AAA despite an, by 153m/s increased velocity (+23.1%, if compared to the 76mm F-34 used there), to the fact that the matallurgic quality of the projectile was not up to the task.

[Mobius]

It's hard to believe that BR-361B is 6.5 kg. when the same shaped BR-350A is 6.3 kg.
Though the Russians give the BR-350, BR-350A, BR-350B, and BR-350SP the same ballistics.
(By some accounts there was no BR-350. Just a variant of BR-350B where the 'B' was left off.)
The shape itself is very strange. Like a tandem projectile. Plus it seems that it would break at the neck on a highly angled armor. If that would help or hurt it's penetration I guess the tests would have to show which.

Russian firing tables seem to indicate the BR-350A penetration is 1mm better at 500m than the earlier BR-350 but 5mm less than the BR-350B.

[Yoozername]

As You might recognize, this is the exact opposite of the findings in the original prooving ground report. Further, the report is explicite in associating the failure to penetrate the TIGER side armor with 76mm AAA despite an, by 153m/s increased velocity (+23.1%, if compared to the 76mm F-34 used there), to the fact that the matallurgic quality of the projectile was not up to the task.

This was my point a page back or so.

The Soviet's designer, when developing the F-22, wanted a longer cased ammunition similar to the 76mm AAA gun. This idea was 'shot down' and it was decreed that the correct path was to share ammunition with the other class of soviet weapons. The irony was that it was also decreed that the F-22 had to have a high elevation so as to shoot at aircraft! The Germans, of course, saw the real potential and developed the F-22 to use German projectiles etc.

The '350A' was supposed to have the front act as some poor man's piercing cap. Very strange. I suppose it was good enough against the early panzers. That is, when the ammunition were even available. Anecdotal evidence exists that KV-1 and T-34 lacked AP altogether and used HE and MG fire.

Did the Germans use the Soviet 76mm AAA weapons with a German projectile also? I know they bored them out and they used German 88mm ammunition?

[critical mass]

If it was meant to be a poor mans cap than it clearly didn´t work as intended. Controlled fragmentation indeed may be an issue at play here, to protect the rather large explosive cavity in the base from premature fracture reaching down to the cavity by sacrificing the upper body? But I´d prefer to read what the russians thought it would do and their design rational before making any conclusions.

[Mobius]

I noticed something strange here. The same factory, lot number and fill date on supposedly two different projectile types.
Is this fake news/documentation ?

Or, possibly artistic license. The illustrator just copied code numbers from actual shells but of different kinds to show where they are located not bothering to correlate them with actual production series codes. The UBR-354A shown here would be a shell made of the obsolete BR-350a projectile assembled in 1940 on a case assembled in 1945. The projectile on the right is illustrated in another shell on this website, the UBR-353. Same factory, lot and assembly year.

[Yoozername]

from a collector site
the UOF-354M HE Cartridge .
UBR-354B APHE

[Yoozername]

From...

https://forum.warthunder.com/index.php? ... mmunition/



Also...translate...

https://ru.wikipedia.org/wiki/%D0%9F%D0%A2-76

So it seems the BR-354 projectile is a pointy APBCHE, the BR-350A projectile is a very strange APBCHE design, the Br-350B is a blunt nosed APC with and w/o HE design.

[Yoozername]

Where's Miles when you need him????

[Mobius]

That's even wrong at the picture of the BR-350A. There's probably as much cloudy information on the Russian 76mm AP as there is on the 7,5cm PaK 40.
The Russian researchers can't find the BR-350 AP bullet on a full charge cartridge. Since they don't have documents on it they claim it doesn't exist. Like the elusive 770 m/s PaK Pzgr 39 somebody had it.
The US and probably British had (at least documents on) the UBR-350 full charge round with the BR-350 AP.
https://digitalcommons.unl.edu/dodmilintel/66/
Since it is mentioned as being used by the ZiS-5 of the KV-1 this probably got sent to the US and/or British by the Soviets along with the tanks and full documentation including the firing table. I doubt if it was captured somewhere post war as that appears to be an early war round replaced later by the BR-350B.
See figure 2 here.
http://www.dtic.mil/dtic/tr/fulltext/u2/014698.pdf

[Yoozername]

The US and probably British had (at least documents on) the UBR-350 full charge round with the BR-350 AP.
https://digitalcommons.unl.edu/dodmilintel/66/

4 • AMMUN IT ION
a. The ammunition listed in these tables is of the
fixed type. A full charge weighing 12.04 pounds and a
reduced charge weighing 8 .1 7 pounds are used with the
lOOmm gun. The 85rnm and the 76mm,guns use only a full
cbarge weighing 5.70 pounds and 2.38 pounds respectively.

The full charge they reference for the 76mm is just the typical 1.08 Kg charge using the 9/7 grains. It isn't the larger 1.4 Kg charge (12/7 grain) seen in the German documentation earlier in the thread.

I would agree, if that is what you mean, that Miles has the worst BR-350A drawing yet...

[Mobius]

The full charge they reference for the 76mm is just the typical 1.08 Kg charge using the 9/7 grains. It isn't the larger 1.4 Kg charge (12/7 grain) seen in the German documentation earlier in the thread.

I'm referring to this site.
http://ww2data.blogspot.com/2015/07/sov ... mm_27.html
Where the only mention of the BR-350 is atop a BR-353 cartridge which they say is a reduced charge. But the pdf data shows it on a UBR-350 which is a full 1.08 kg charge.
Why solid AP is on a reduced charge is curious. It is lighter than the 76mm mountain gun.