Monday, 30 October 2017

Pak 40 Discovery

"To the Deputy People's Commissar of Defense, Lieutenant General of the Tank Forces, comrade Fedorenko
August 18th, 1942

I report that, according to documents, the German army possesses 7.5 cm mod. 1940 anti-tank guns.

The gun fires regular 7.5 cm mod. 1939 armour piercing rounds, 7.5 cm mod. 1938 HEAT rounds, special 7.5 cm mod. 1940 armour piercing rounds (with a hardened core), and 7.5 cm mod. 1934 HE rounds.
The effect of the armour piercing rounds is as follows:

Against the T-34 tank:
The mod. 1939 shell penetrates the front from up to 500 meters, the rear from up to 1000 meters, the upper side from 1200 meter.

Against the KV (with 7.62 cm gun):
The mod. 1939 shell penetrates the turret armour (75 mm), turret platform, and hull from up to 1000 meters.

The mod. 1938 shell penetrates the aforementioned armour at all effective ranges.

Against the KV with applique armour:
The mod. 1939 shell penetrates the turret armour (100 mm) from up to 100 meters, the turret platform from up to 300 meters.

The mod. 1940 shell penetrates the front armour (90 mm) from up to 200 meters and the lower from plate from up to 400 meters.

Chief of the 2nd Directorate of the Main Intelligence Directorate of the General Staff, Colonel Ratov
Military Commissar of the 2nd Directorate of the Main Intelligence Directorate of the General Staff, Brigade Commissar Kiselev
Chief of the 1st Department of the GRU 2nd Directorate, Khlopov"


  1. The ranges given here are from german instruction manuals. The ranges given therein take into account a target angle of 30° deviating from ideal.

  2. I would expect penetrations against the T-34 to be possible at larger distances (1300 meters as per Yugoslavian tests), maybe is the effect of the target angle then.

  3. The difference between 60° at 0° TA and 60° at 30° isn´t so large. Using vectors, You obtain a compound netto angle of 64.34°.

    However, the definitions are stricter in these FT instructions. I.e. the reliable 100% criterium is used, which will result in different ranges to the split criterium applied in the post war trials(split difference between success and failure).

  4. @Alejandro, This was for a 770 m/s gun. Which the Soviets had and used in a spare track test.
    The Yugoslav tests could of been of a 790 m/s gun. Plus as Critical Mass put it the Yugo tests used the US 50/50 criterion, while the German used a 100% criterion while the Russians an 80/75.

  5. Mobius,

    there were plans dating to 1943 intending to increase the muzzle velocity of the PAK40 by issuing a larger charge (compare 38417/43g, dated 13th & 16th of sept. 1943).

  6. The MV of the Pak 40 has confusing documentation. It is 790 m/s and 770 in others about the same time frame 1942-1943.
    In late 1944 it goes down to 750 m/s.