The MG3 (short for Maschinengewehr 3, meaning "Machine Gun 3") is a modernized version of the MG 42 general purpose machine gun. It was manufactured by Rheinmetall GmbH for the West German Bundeswehr after that nation's rearmament in the 1950's. The MG3 was used universally by the German federal armed forces and was widely exported and made under license by several nations. The MG3 is chambered for the NATO standard 7.62×51mm NATO (.308) round. In contrast, the MG42 used the 7.92×57mm Mauser cartridge in German service since 1905.
The MG3 is a recoil-operated, crew-served, air-cooled machine gun that can be fired from an integral bipod or, for fixed use, on the Feldlafette buffered tripod or a pintle. It fires only in full-auto and is fed from the left by a disintegrating-link belt. It has been replaced in German service as the squad automatic weapon by the 5.56×45mm MG4, but retains its place as a section machine gun and vehicle-mounted weapon.
At first glance, it is commonly confused with the MG42 from which it was developed. Both weapons look alike and function identically, thus many parts are interchangeable. The MG3 retains the very fast cyclic rate-of-fire (1000+ rds/min) and quick barrel change feature of its predecessor and is, likewise, made almost entirely of sheet steel pressings and stampings.