Did the Soviets test fire every new SKS, AK, Mak, etc -- proofing vs test firing

[Boris Badinov]

Did the Soviets follow the standards set by the C.I.P. ?

Was every barrel proofed in the white, prior to assembly-- a la black powder proofing-- and then test fired again after final assembly with overpowered cartridges?

Or did the Soviets perform test firing on sample batches of finished small arms?

[running-man]

I don’t think there’s going to be a definitive answer Boris. The Soviets were pretty serious about the quality of their arms industry so I can’t imagine they wouldn’t have proof tested and zeroed each and every one, but I’ve got nothing but intuition to back that up.

I do remember reading long ago that it was thought there were common ‘proof marks’ on the left side barrel lug (circle with a TK comes to mind, or maybe it was a circle П,  honestly could be almost anything I suppose).

[jstin2]

 If every rifle was test fired after assembly, they would have to be cleaned due to corrosive ammo.

[Boris Badinov]

The barrels on Chinese sks bear the Soviet proof marks long after the sino-soviet split. Romanian M59s also bear known soviet proof marks.

I've long thought this to be strong indication that pressure testing -- at least for the soviet sks bbls-- was done prior to assembly.