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Type 99 Mark 2 file photo [27143]

Type 99 Mark 2 Aircraft Autocannon

Country of OriginJapan
TypeAircraft Autocannon
Caliber20.000 mm
Length1,890.000 mm
Weight34.000 kg
Ammunition Weight0.13 kg
Rate of Fire400 rounds/min
Muzzle Velocity750 m/s



This article deals with a Japanese aircraft autocannon variant of the Oerlikon 20-millimeter design. For other aircraft autocannon variants, please see Type 99 Mark 1 and 20 mm MG-FF Oerlikon. For the design's land and ship-based anti-aircraft applications, please see 20 mm Oerlikon anti-aircraft.

In 1935, the Japanese Navy began searching for 20-millimeter autocannons/machine guns to arm future fighter aircraft. It settled on the designs by the Swiss firm Oerlikon in 1937. A newly formed company, Dai Nihon Heiki KK, established by retired Navy officers, purchased two licenses from Oerlikon, one for Oerlikon FF and another for Oerlikon FFL, to produce Type 99 Mark 1 Machine Guns (Kyukyu Shiki Ichigo Kizyu) and Type 99 Mark 2 Machine Guns (Kyukyu Shiki Nigo Kizyu), respectively.

Type 99 Mark 2 machine guns were heavier than the Mark 1 weapons, fired a larger cartridge, had a slower rate of fire, and had a higher higher muzzle velocity. There were only fixed applications for Mark 2 machine guns (meanwhile, Mark 1 were also installed on flexible mounts). Mark 2 machine guns were introduced in 1942, 3 years after the Mark 1 design, and quickly gained favor over their Mark 1 counterparts. They were mounted aboard later variants of A6M Zero fighters, among many other models. These weapons were initially fed from drums, but later variants introduced belt-feeding capability.

Source: Wikipedia


Last Major Revision: Nov 2017


Japanese Navy Type 99 Mark 1 (top) and Type 99 Mark 2 (bottom) aircraft machine guns, circa 1945

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Type 99 Mark 2 Aircraft Autocannon Photo Gallery
Japanese Navy Type 99 Mark 1 (top) and Type 99 Mark 2 (bottom) aircraft machine guns, circa 1945

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