Mine will shoot Wolf pretty good, but I mostly shoot reloads. I also use Wolf primers and they go bang every time in the 7.62x39 reloads that I use. I think it is more of an issue with excessive headspace in both the NEF and Rossi in the 7.62x39 that is causing mosty of the problems. This can be overcome by seating the bullet out a bit further, or just neck sizing the reloads.
I came to this conclusion after removing the barrel and inserting a loaded shell into the chamber. Then I pushed the shells that did not go off, (which were not many), in as far as they would go, and they went in probably a .010 of an inch.. worst case. This would make the cartridge go almost out of the range of the firing pin.
Just my observations for what they're worth. Good luck.