In connection with your questions on 37 mm guns produced by the NKV, I report the following.
- Technical Council member comrade Tolochkov misinformed you, giving you imprecise information about OKB-16's gun.
As facts at factory #174 show, the number of hours spent on producing the OKB-16 gun is over 450 hours, out of which 100 is spent on fine tuning and 350 on machining.
The production of OKB-15's gun takes 286 hours of machining and then a negligible amount of time for fine tuning: the guns can be shipped immediately.
- Comrade Tolochkov "forgot" to inform the BTU the most important thing, the fact that the OKB-16 gun's muzzle velocity is 790 m/s, which allows it to penetrate 35-38 mm of armour, unlike the 50-60 mm that OKB-15's gun can penetrate. The reduced muzzle velocity is explained by the fact that the OKB-16's gun has a light and movable barrel. The barrel moves back and eats up velocity of the shell.
- Similarly, the members of the Technical Council did not inform the BTU that OKB-15 developed AP-I shells for their gun. It is enough to say that these shells, when loaded into the OKB-15 gun, can penetrate a steel plate up to 100 mm thick.
Shpitalniy was trying to squeeze out Nudelman's 37 mm gun, but that didn't help him. His design didn't make it into the T-70 at all and only saw limited installation into the Il-2 before being replaced by Nudelman's design.