MG 81 machine gun

MG 81
MG 81 (upper) and MG 81Z (in box)
Type	Machine gun
Place of origin	Nazi Germany
Service history
Used by	Nazi Germany
Wars	World War II
Production history
Variants	MG 81Z
Specifications
Weight	6.5 kg (14.33 lb)
Length	965 mm (38.0 in) (with flash hider)
Barrel length	475 mm (18.7 in)
Cartridge	7.92×57mm Mauser
Caliber	7.92 mm
Action	Recoil-operated
Rate of fire	1,400–1,600 rounds/min
Muzzle velocity	790 m/s (2,592 ft/s)
Feed system	Belt-fed

The MG 81 was a German belt fed 7.92 mm machine gun, used in flexible installations in World War II Luftwaffe aircraft, replacing the older drum magazine-fed MG 15.

The MG 81 was developed by Mauser as a derivative of their successful MG 34 infantry machine gun. Development focus was to reduce production cost and time and to optimize for use in aircraft. Developed in 1938/1939, it was in production from 1940 to 1945.

A special twin-mount MG 81Z (the Z suffix stands for Zwilling, meaning "twin") was introduced in 1942. It paired up two of the weapons on one mount to provide even more firepower with a maximum rate of fire of 3200 rounds/minute without requiring much more space than a standard machine gun.

The MG 81Z was found in many unique installations in Luftwaffe combat aircraft, such as a pair of MG 81Z (for a total of four guns) installed in the hollow tail cone of the Dornier Do 217. Designated R19 (R for Rüstsatz) as a factory designed field conversion/upgrade kit, it allowed the pilot of the Do 217 to shoot at pursuers.

Another application was the Gießkanne (Watering can), an externally mounted pod with three gun pairs, making a total of six guns and their ammunition. Able to fire 9000 rounds per minute, this was attached to Junkers Ju 87 or Ju 88 in an underwing mount and used to strafe ground targets.