I picked up a nice used Mini-30 at a gun show last month. SS and it came with a Hogue stock and flash/Comp muzzle gizmo. One reason I bought it is that I had an unmounted Nikon Monarch 2 x 7 scope needing a home. Well, even though the trigger is creepy I get very good groups at 100 yds...I am impressed. Issue: the rifle works perfectly with Wal Mart Winchester brand ammo (7.62 x 39). Of course I wanted to be able to use the dirt cheap non-corrosive Wolf brand Russian ammo that is available everywhere. My rifle doesn't like it. Out of 5 rounds three will not fire....but if I re-use them (after a decent time to make sure no hang fire) they will fire. So I ordered and installed an aftermarket heavy hammer spring. I bought more ammo from another lot and still had the same problem. Again I tried the Winchester ammo and function was perfect. Finally I visually compared a single round each of the Wolf and Win ammo. Guess what? The cartridges are visually different in shape. The location of the shoulder and the angle of the shoulder are noticeably different. Anyone else had this experience?