The Heckler and Koch G36 is a German 5.556x45mm assault rifle. It replaced the G3 rifle. It is gas operated and fires a 30 round magazine or a 100 round C drum.
The G36 uses a closed rotary bolt. It is interchangeable with most of its family. The G36 uses a free floating barrel which is attached by a nut. Th3 G36 does not require tools to disassemble it.