The HK21 is a belt-fed general-purpose machine gun using the same roller-delayed blowback operating system as the G3 battle rifle. It fires the standard 7.62x51mm NATO cartridge and can also be converted to fire from G3-type box magazines. Used by German and Portuguese forces and exported to numerous countries. Type: Machine Gun Action: Semi/Full-Auto Caliber: 7.62x51mm Capacity: 200 Year introduced: 1961, Germany Weight: 275.2 oz Overall length: 44.1" Status: Discontinued Military use: Yes Intended use: military