Also, those rifles are prone to fouling. Make sure the the inside of the reciever is clean, including the are where the bolt locks up. It sounds as though it is short cycling, or not locking up. Pay close attention to the boalt when cleaning. As stated, the gas system is very simple to disassemble and clean. Heres a schematic http://www.brownells.com/.aspx/sid=1...sdetail/7400_4
also, they need to be lubed properly to function.