Approve Deputy Peoples Commissaar of the Tank industry of the USSR Popov 15 November 1942
    Brief Technical Report. 
About the development of means for tank
    protection against sub-caliber and  rounds.
  
  
    During the war, new ammunition types have entered the service of the German
    army - sub-caliber and cumulative shells. The test firing of the hull of
    T-34 tank from the German 75mm gun and 76mm domestic gun with cumulative
    shells have shown the following:
    
I. The strength of the hull of T-34 tank against the cumulative
    shells.
  
| Hull part | Tank bearing angle | Strength of part | |
|---|---|---|---|
| 75mm German cumulative shells | 76mm domestic cumulative shells | ||
| Frontal hull plates | 0 | No penetration | No penetration | 
| Hull sides | 90 | Penetrated | penetration | 
| Hull sides | 60 | No Penetration | Penetrated | 
| 90 | No penetration | Penetrated | |
| Hull rear | 180 | No penetration | No penetration | 
| Turret | 90 | No penetration | Penetrated | 
    From the above table it is evident that domestic shells have better
    penetration ability than the German ones as the former ones penetrate only
    the sides of the hull of a T-34 tank and only from angles that are close to
    normal.
    
The pecularity of these shells is that due to their HE capability they
    do not loose their penetrative capabilities with distance. Because of that
    the hull sides of a T-34 tank can be penetrated from a large distance.
    
Regarding the HE capability of these shells, it is quite significant
    and is even slightly bigger than that of ordinary HE shells. 
Moreover,
    when impacting to the hull sides near the bottom, Подкрылки? Or transmission
    parts, cumulative rounds destroy them and make the tank inoperable. On
    impact to the lower part of the turret the roof is bent inwards or even
    breaks. When hitting the rear side, the hatches are torn off, exhaust pipe
    protection is torn off, bolt joints are destroyed.
  
РГАСПИ. Ф. 644. Оп. 2. Д. 115. Л. 80
