World War II Database

Country of Origin	Japan
Type	Aircraft Autocannon
Caliber	20.000 mm
Length	1.330 m
Weight	23.000 kg
Ammunition Weight	0.13 kg
Rate of Fire	520 rounds/min
Muzzle Velocity	600 m/s

Contributor: C. Peter Chen

ww2dbase

Type 99 Mark 1
existing 353

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 1 machine guns were used in both fixed and flexible applications. The fixed installation application was developed first, mounted in the wings of the early variants of A6M Zero fighters. Each weapon was fed by a 60-round drum. The flexible application was first seen on G3M bombers. The drum limitation was later addressed in the 4th variant of the Type Mark 1, which introduced belt-feeding. Mark 1 weapons fired a smaller cartridge than their Mark 2 counterparts, and enjoyed a higher rate of fire, although they had a lower muzzle velocity. Toward the end of the war, they slowly fell out of favor, and were slowly overtaken by Mark 2 machine guns.

Source: Wikipedia ww2dbase

Last Major Revision: Nov 2017

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