The MG is a short-recoil operated, air cooled, belt fed weapon which fires from an open bolt. The barrel is quick-removable, and can be replaced in less than six seconds by a properly trained crew. The action of the weapon is operated by the recoil of the locked barrel, assisted by a muzzle booster which uses pressure from the muzzle blast to increase the recoil impulse. This is a simple and solid system.
MG 1: Rheinmetall variant of the MG 42, most notably rechambered to fire 7.62×51mm NATO.
MG 1A1 (MG 42/58): As MG 1, but with sights properly calibrated for the new round. Sights refitted to existing MG 1s.
MG 1A2 (MG 42/59): MG 1A1 variant; product improved with longer ejection port, heavy bolt and friction ring buffer.
MG 1A3: MG 1A2 variant; product improvement of all major components.
MG 1A4: MG 1 variant; for fixed mount armor use.
MG 1A5: MG 1A3 variant; MG1A3s converted to MG1A4 standard.
MG 2: Designation for all wartime MG 42s rechambered to 7.62×51mm NATO.
MG 3: MG 1A3 variant; product improved with AA rear sight.
MG 3E: MG 3 variant; reduced weight model (roughly 1.3 kg lighter), entered into late 1970s NATO small arms trials.
MG 3A1: MG 3 variant; for fixed mount armor use.