The Heckler & Koch G36 is a selective-fire 5.56mm assault rifle, firing from a closed rotary bolt. The G36 has a conventional layout and a modular component design. Common to all variants of the G36 family are: the receiver and buttstock assembly, bolt carrier group with bolt and the return mechanism and guide rod. The receiver contains the barrel, carry handle with integrated sights, trigger group with pistol grip, handguard and magazine socket.