45 mm APCR Penetration

 "To the Chair of the State Committee of Defense, comrade I.V. Stalin

We present the main results of proving grounds trials of 45 mm subcaliber armour piercing shot designed by Military Engineer 1st Class comrade Burmistrov.

The shot with heavy and hard tungsten alloy shows the best results. This shot satisfies the requirement of penetrating at least 60 mm of armour with the resistance coefficient of at least 2400 at an angle of 30 degrees at a range of 300-500 meters. They considerably increase the power of the 45 mm model 1932/37 anti-tank gun.

Shot	Muzzle Velocity	Range	Angle of impact	Thickness	Coeff- Icient	Result
Exp. 1st variant	937	500	35	50	2580	All shots gave complete penetration.
Exp. 2nd variant	1016					Complete penetration. Some shot gave deep dents.
Stock	760					Small dents
Exp. 1st variant	937	300	34	60	2500	All shots gave complete penetration.
Exp. 2nd variant	1016					Complete penetration. Some shot gave deep dents.
Stock	760					Small dents
Exp. 1st variant	937	150	0	90	2300	Complete penetration.
Exp. 2nd variant	1016					Complete penetration.
Stock	760					Small dents

Experimental and stock 45 mm armour piercing rounds were also tested against a captured German tank.

Shot	Muzzle Velocity	Range	Angle of impact	Thick-ness	Tank part	Result
Exp. 1st variant	937	500	10	60	Lower front	Complete penetration. Brakes broken behind the armour.
Exp. 2nd variant	1016	500	10	60	Lower front	Two complete penetrations, one shot gave a deep dent.
Stock	760	500	10	60	Lower front	Small dents
			10	50	Upper front	Small dents
			10	30	Turret side	Complete penetration

The best results in terms of penetration and beyond armour effect were given by the 1st variant of experimental shot. Drawbacks include lower precision and expenditure of tungsten for making cores. 2nd variant experimental shot has lower penetration but better precision and uses half as much tungsten for cores.

Based on the above results, I consider it most reasonable to accept both variants of 45 mm subcaliber AP shot into service, produce batches of both in April in the volume of at least 25-30,000 units, and begin mass production in May. Subject production shot to trials on proving grounds and on the battlefield in order fully evaluate both types of shot.

We attach a draft State Committee of Defense decree.

Chief of the GAU, Colonel-General of Artillery Yakovlev
Military Commissar of the GAU, Divisional Commissar Novikov
March 28th, 1942"

"Attachment:

45 mm subcaliber shot type 1

• Weight: 900 grams
• Core weight: 500 grams
• Core diameter: 28 mm
• Hull steel: carbon steel type 5, unit weight 7.85
• Core alloy: Reniks-6 tungsten alloy, unit weight 14.6 
• Driving band: copper M1-MZ type
• Ballistic cap: iron
• Muzzle velocity: 973 m/s
• Maximum pressure: 2700 kg/cm²
• Gunpowder charge: 6/7 sv 3/38R, 374 grams
• Precision at 500 meters:
• Vertical deviation: 0.41 m
• Horizontal deviation: 0.32 m
• Penetration of armour with coefficient of at least 2400 at 30 degrees:
• 50 mm at 700-800 meters
• 60 mm at 300-450 meters

Via Padikovo museum.