"To the Chair of the Committee of Defense, comrade I.V. Stalin
I provide you with the proving grounds results of 45 mm subcaliber armour piercing ammunition designed by Military Engineer 1st Grade Burmistrov.
The best results were obtained with shells using a heavy and hard tungsten alloy core. These shells can achieve the objective of penetrating 60 mm of armour with a coefficient of resistance of at least K=2400 at an angle of 30 degrees from a range of 300-500 meters and effectively improve the power of the 45 mm mod. 1932/37 anti-tank gun.
I provide you with the proving grounds results of 45 mm subcaliber armour piercing ammunition designed by Military Engineer 1st Grade Burmistrov.
The best results were obtained with shells using a heavy and hard tungsten alloy core. These shells can achieve the objective of penetrating 60 mm of armour with a coefficient of resistance of at least K=2400 at an angle of 30 degrees from a range of 300-500 meters and effectively improve the power of the 45 mm mod. 1932/37 anti-tank gun.
Shell | Muzzle velocity | Range | Impact angle | Thick-ness | Armour coefficient | Notes |
Variant #1 | 937 | 500 | 35 | 50 | 2580 | All shells penetrated fully. |
Variant #2 | 1016 | 500 | 35 | 50 | 2580 | Penetrations, some hits gave deep dents. |
Stock AP | 760 | 500 | 35 | 50 | 2580 | Shallow dents. |
Variant #1 | 937 | 300 | 34 | 60 | 2500 | All shells penetrated fully. |
Variant #2 | 1016 | 300 | 34 | 60 | 2500 | Penetrations, some hits gave deep dents. |
Stock AP | 760 | 300 | 34 | 60 | 2500 | Shallow dents. |
Variant #1 | 937 | 150 | 0 | 90 | 2300 | All shells penetrated fully. |
Variant #2 | 1016 | 150 | 0 | 90 | 2300 | All shells penetrated fully. |
Stock AP | 760 | 150 | 0 | 90 | 2300 | Shallow dents. |
Stock and experimental 45 mm AP shells were also fired at a captured German tank.
Shell | Muzzle velocity | Range | Impact angle | Thick-ness | Armour component | Notes |
Variant #1 | 937 | 500 | 10 | 60 | Lower front plate | Complete penetrations. The brake bar behind the armour is destroyed. |
Variant #2 | 1016 | 500 | 10 | 60 | Lower front plate | Two complete penetrations, one shell resulted in a deep dent. |
Stock | 760 | 500 | 10 | 60 | Lower front plate | Shallow dent. |
15 | 50 | Upper front plate | Shallow dent. | |||
10 | 30 | Turret side | Complete penetration. |
The best penetration and effectiveness is achieved by experimental shells of the first variant. Drawbacks of these shells include slightly reduced precision and use of a lot of tungsten in production. Experimental shells of the second variant are less effective than the first type, but have better precision and use half as much tungsten.
Based on the obtained results, I consider it reasonable to put both variants into production and produce 25-30 thousand units of both types in April, and begin mass production in May. Mass production shells should be tested on proving grounds and in battle in order to fully evaluate them.
The decree draft is attached.
Chief of the Red Army GAU, Colonel-General of Artillery, Yakovlev
Military Commissar of the Red Army GAU, Divisonal Commissar Novikov"