Bought a brand new VEPR in 5.45x39. LOVE IT!!! Love shooting it. Clean it religiously, using the Russian surplus corrosive stuff. Last two trips to the range started getting misfires, about 2 in 10 of Wolf ammo, 1 in 15 of the Russian mil surplus. See a striker hit but didn't fire, they fire typically on second pass. Started trouble shooting and I can't find the problem. Tried swapping out the hammer spring and various firing pins. I 'think' I see a possible bur or corrosion in the very end of the firing pin passage of the bolt. Anyone got a slick way to pass something abrasive up there and see if I can get it smoothed out?
If not, anyone got any thoughts on which bolts will work as a replacement in a Russian VEPR? I'm told Bulgy but the bulgy firing pin is decisively shorter than the VEPR original.
I had the same problem in a Bulgarian kit.
Turned out the problem was not enough tension on the hammer spring.
Make sure the rear "legs" of the spring are both resting on the trigger, and give the legs more of a downward bend to increase tension. That may well "cure" the misfires.
What happens is that the spring legs get bent upward during disassembly and reassembly, and you may not notice.
I disassembled mine several times looking for some problem with the bolt and each time I reassembled the misfires got worse.
I just by chance noticed that the downward bend in the legs wasn't as much as when the problem first showed up in the new rifle.