The People's Commissariat of Armament developed an experimental batch of supercaliber HEAT rounds for the 45 mm anti-tank gun based on a captured German sample to be used against heavy tanks. These rounds were tested at the Sofrino artillery proving grounds at a range of 100 and 200 meters.
On all impacts, the round penetrated the 100 mm plate completely with a 70-80 mm wide breach, caused spalling on the other side, sent fragments flying in front of and behind the plate, and created a strong flash of flame behind the plate.
A barrel of oil placed behind the place was penetrated by fragments and ignited when the round hit the plate.
Melted edges of the breach and melted fragments give an illusion of the armour being burned through.
In order to determine the suitability and mass production of these rounds, we ask your decision to produce and test on the front lines 200 supercaliber HEAT rounds.
The test report and photographs are attached.
July 10th, 1942"
"Sofrino Artillery Proving Grounds
June 29th, 1942
On June 29th of this year, trials of a supercaliber HEAT round for the 45 mm mod. 1932 anti-tank gun against a 100 mm plate were performed. Firing took place from 100 and 200 meters, with pressure inside the gun of 1000 kg/cm² and muzzle velocity of 115.3 m/s. Firing was performed without sights.
- From three acceptable shots from 100 meters, three complete penetrations were achieved with a diameter of 65-70 mm.
- From 200 meters, one round hit the plate and caused a 90x50 mm breach.
- A barrel of oil placed 0.5 meters behind the plate ignited when the round hit.
- In comparison, two shots were made from a captured 37 mm supercaliber HEAT round. One of those rounds hit the 100 mm plate and penetrated, giving an 85 mm breach.
- When the supercaliber HEAT round hits a 100 mm plate from 100 meters or 200 meters, a breach is achieved.
- A complete penetration results in oil behind the plate igniting.
- When the rounds hit, fragments are thrown in front of and behind the plate, a flash of flame is observed behind the plate, and a loud noise is heard."