Translation:
IV. Determination of armor penetration
Shooting was conducted using the 20mm ShVAK cannon and the 12.7mm DShK machine gun against 20mm thick armor plates, cemented and homogenous, at normal as well as at 30° obliquity.
Detailed properties of the armor plates are listed in addendum 4.
Shooting was conducted using the following types of ammo:
1) 20mm B-3, P-85, factory 187, year 1941, propellant VTUF [Rifle Powder ???? Phlegmatzied]
2) 20mm NV-200, propellant reloaded by NII-6 in 1941.
3) 12,7mm B-32
4) 12,7mm B-30
Detailed journal of the shooting is presented in addendum 7, from which it can be seen that:
20mm ShVAK cannon:
1.The 20mm AP-I shell does not perforate a 20mm cemented plate from 135m distance at 30° angle nor at normal.
The same shell does not perforate a 20mm homogeneous plate set at 30° angle from 135mm, but perforates it at normal at distances up to and including 400m.
2. The 20mm AP-I shell NV-200, with an increased muzzle velocity, does not perforate a 20mm cemented plate set at 30° from 135m, same for a homogeneous plate.
The same shell produces 100% perforations when fired against a 20mm homogeneous plate set at normal at distances up to and included 500m.
12,7mm DShK machinegun:
1. The 12,7mm B-30 bullet does not perforate a 20mm cemented plate set at 30° from 135m, same for a homogeneous plate.
2. The 12,7mm B-30 bullet produces 20% of perforations when fired against a 20mm cemented plate set at normal at 135m.
3. The 12,7mm B-32 bullet produces 50% perforations when fired against a 20mm homogeneous plate set at normal at distances up to and included 400m.
-- two paragraphs are omitted as they are just a summary of the previous results --
To determine the armor penetration capabilities of both guns under different conditions they were tested against 15mm thick cemented plates set both at normal and at 30°. The results are presented in the table in addendum 8 from which it follows that...[end of page]