One thing I look for in a used AK, and I’m sure with the experience on this board someone else here has had a similar problem, is the floating (or even spring loaded) firing pin. The Valmet I purchased seemed to be in really good shape and field stripping showed no signs of neglect or abuse. After a few rounds down range, the gun suddenly went full auto. Before I could get my finger off the trigger the ass end of the third round blew off while the bolt was out of battery. Apparently the previous owner like to keep the bolt well oiled and the coke build up on the pin and pin recess was so excessive that the pin stayed forward (Thompson M1A1). The reason I bring this up is that could have been a serious health issue. The dust cover contained most of the casing. A left handed shooter might not have been as lucky as I.
Hey, isn’t OBL left handed?
The point is when buying a used gun, even an AK; it’s prudent to REALLY look it over before firing. If you can’t do it, find someone who can. I figured; hey, it’s an AK. What can go wrong?
After I got the remainder of the casing out of the chamber and the projectile out of the barrel, cleaned the carbon off the firing pin, the gun worked perfectly. Very accurate, too.