US Patent 7966761 Automatic or semiautomatic rifle with folding stock

An automatic or semiautomatic rifle having a receiver and a bolt carrier movably coupled to the receiver. An action system is connected to the bolt carrier for cycling the bolt carrier in the receiver. A receiver extension is connected to the receiver, at least part of the action system extending into the receiver extension. A folding stock is connected to the receiver. The receiver extension is located within the folding stock.