I had the same think happen with one of my AK's. The bolt goes almost to the point of fully closing but it wont. It was basically headspaced wrong. There wasn't enough room for the round to fully seat and bolt to close. I sent it back and they fixed it. Since then and 1000+ rounds later i have had no more problems.It was a brand new rifle. I watched the guy take it out of the plastic wrapper. As far as dropping a round in the chamber and letting the bolt forawrd. The bolt still wouldn't close all the way. It had like a half inch seperation before being closed all the way. I mean it obviously wasnt the mags we just literall tried everything we could. When there was no round in the chamber the bolt could close all the way. The round wouldn't go completly in the chamber through. It would stick out like a MM. I don't know if this is how all AK's work because all I know is that when I rack a round in my MAK90 it goes bang everytime. I don't have to pay attention to the bolt. Keep the ideas coming!!!