I have a CETME with the US made CAI receiver. It fires just fine for the most part but it sees to jam alot. I clean it thoroughly each time i fire it and it works fine for the first few rounds then after about 20 rds it jams almost every time. The extracted brass gets wedged behind the bolt and even when it ejects clear it is chewed all to hell. The spent brass is unusually fouled and dirty. I have only used british made NATO surplus fmj. I have used two types of G3 mags. Would it make a difference if i used origional CETME mags? Anyone else have this trouble? I am wondering if i should sand the chamber a bit. Would a new bolt carrier be the answer? Also...would a G3 parts kit (bolt, hand grips, adjustable stock) fit my weapon? I am quite frustrated. I really love the way the gun shoots aside from the infuriating jamming troubles. Any help would be greatly appreciated. Thanks.