MK 108 cannon
The MK 108 (German: Maschinenkanone - Machine Cannon) was an autocannon (30mm calibre) manufactured in Germany during World War II by Rheinmetall-Borsig for use in aircraft.
The weapon was developed as a private venture by the company in 1940 and was submitted to the Reichsluftfahrtministerium (RLM - Reich Aviation Ministry) in response to a 1942 requirement for a heavy aircraft weapon for use against the Allied bombers appearing en masse in German skies. Testing verified that the cannon was well-suited to this role, requiring on average four hits with high-explosive ammunition to bring down a heavy bomber such as a B-17 Flying Fortress or B-24 Liberator and a single hit to down a fighter. In comparison, the otherwise excellent 20 mm MG 151/20 required an average of 25 hits to down a B-17.
The MK 108 was quickly ordered into production and was installed in a variety of Luftwaffe fighter aircraft, including the Messerschmitt Bf 109, Focke-Wulf Fw 190, Heinkel He 219, Messerschmitt Me 163, and Messerschmitt Me 262. Apart from the high-explosive Minengeschoss (or "mine" round), incendiary rounds were also produced for it.
The cannon proved to be very effective and reliable due to its simple blowback operation, its main shortcoming being that its trajectory drooped considerably due to its low muzzle velocity, making effective firing ranges short and aiming a challenge. Otherwise, it was simple to manufacture and maintain and its compact size and weight made it ideal for aircraft installation. The cannon's distinctive heavy pounding sound gave it the nickname pneumatic hammer amongst Allied aircrews.
The MK 108 was also fitted to night fighters in an unusual installation, called "Schräge Musik" (German: "Jazz Music", literally "slanting music"). In this configuration, the cannons were mounted in the fuselage, aiming upwards at an oblique angle. This allowed the night fighter to attack bombers, almost always undetected, by approaching from underneath the enemy aircraft. This installation was so effective that discovery and news of its adoption was slower than usual in reaching British night-bombing forces, as there were rarely any survivors from the attacks to report the new threat.
Specifications
- Calibre: 30 mm
- Length: 1057 mm (3 ft 6 in)
- Weight: 64 kg (141 lb)
- Rate of fire: 650 rounds/min (later models 850 rounds/min)
- Muzzle velocity: 540 m/s (1,770 ft/s)