Trivia: The Russians had an aircraft cannon — YVa, I think, in 20 or 23 mm — that used a helical feed rotor. The feed rotor was not heat treated for hardness. Instead, as the rotor got burred, the Soviet armorer dressed the burrs with a file and put the gun in service. If the rotor got deformed, it was thrown out and a new rotor was fitted. The idea behind not heat treating the part was ingeniously simple: (1) it was easier to make; (2) not heat treating meant more parts in less time; (3) burrs meant the part was approaching the end of its service life and would need replacing; (4) expensive inspection gages were eliminated.
Aside from the loose surplus, I’ve never had Russian surplus not go bang. Out of three 1000 rd. case purchases, I’ve only had a half-dozen misfires, stovepipes, or hangfires. It usually always goes bang!