Other M53 owners over here are reporting that S&B 8x57 ammo doesn't work so good in machine guns...
Guess what brand of ammo I've stockpiled...
...good thing I've got several ruptured case extractors in my arsenal... guess I'm gonna get a lesson on how to use these things whenever I get around to firing these guns...
This is most interesting...
Mic the chamber and then the rounds.
Also the primers might be to light and with the free floating firing pin causing it to go off while chambering.
Seems like almost a discharge before entering into battery.