IN any case, take out the bolt and look in the chamber. Doe the walls of the chamber look smooth and shiny? Or dull or pitted? With thousands and thousands of surplus used MNs coming in the country, it would suprise me if there were no duds in the mix of old communist made hardware. I mean, in WW2 the Russian factories were cranking them out in unbelievable quantities on a daily basis. My 1943 rifle looks like it was shaped with a file on the receiver. Like almost handmade. Suprisingly, this rough looking mega mass produced rifle shoots excellent groups. Might be the rebuild barrel. I guess the sticky cases is why they left the bayonets on them all the time! Little more effective than using it as a club, I guess.
Your gun is like your nose, it is just wrong for someone else to pick it for you!