Hey DrewArtist! I own several Century builds. My Yugo M70AB needed only some polishing with a dremel to get the disconnector to loosen up after firing, then it was awesome.(I would have to push the trigger forward after a shot before I did this) After inspecting my AES-10(RPK) I discovered metal shavings inside the bolt that was binding up the firing pin. I just took it apart and dumped the shavings and it fires great. The best thing you can do with any gun you get is inspect it and clean it before you heat it up. Good luck!