Not all guns will have problems with the Russian ammo. Though I see many problems at my range when it is used with western made firearms.
The lacquer will build up in the chamber of the firearm as it heats. After so much build-up a round will get stuck in the chamber. Former Eastern-Block weapons are usually built for reliability and eat this stuff up with no problems.
AR15's are suseptable to this and I've seen case heads torn off by the extractor because a casing is "lacquered" into the chamber.
I've seen several pistols with the same problem. I hope yours is up and running again soon.