MK 103 cannon

The Rheinmetall-Borsig MK 103 was a German 30 mm caliber autocannon that was mounted in German combat aircraft during World War II. Intended to be a dual purpose weapon for anti-tank and air-to-air fighting, it was a development of the MK 101 cannon. Compared to the MK 101 it was lighter, faster firing and had a higher muzzle velocity and used a belt feed allowing it to potentially fire much more ammunition in a single mission. The MK 103 used electrically primed rather than percussion primed ammunition. The firing mechanism differed from the recoil operated MK 101 in that it used a combination of gas and recoil operation. After firing, gas pressure serves to unlock the breech, while barrel recoil was used to cycle the action (eject spent cartridge and load a fresh one).

However, through a combination of lower grade steels and lighter components, the mechanism was not as strong as the MK 101. To counteract this weakness HE ammunition used a reduced load of propellent, resulting in a lower muzzle velocity and rate of fire. Armour piercing ammunition still used a full load of propellent as the resulting higher muzzle velocities were felt to be worth the risk. The MK 103 entered service in 1943.

The original specification for the weapon called for it to fit inside the engine mounting (possibly as a "Motorkanone", firing through a hollow propeller hub) of aircraft, however the final weapon was just too large. A modified version of the weapon, the MK 103M was developed and possibly tested but probably never saw active service.

Developed alongside the MK 103 was a lighter short-ranged MK 108 cannon which fired the same projectiles using a smaller cartridge case with less propellent.

The Focke Wulf FW 190A-8 "Sturmbock" bomber-destroyer sub-series in 1944 used a pair of faired MK-103 cannons under the wings, and later versions had a fairing over the barrel and vertical ejecting muzzle brake.

pecifications

*Weight;145 kg
*Length:2335 mm
*Muzzle velocity (HE/AP): 760 to 940 m/s
*Rate of fire (HP/AP): 380 to 420 rounds/min

References

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