Type 4 20 mm twin AA machine cannon

Type 4 20 mm twin AA machine cannon was an Imperial Japanese Army (IJA) anti-aircraft gun. It consisted of two Type 98 20 mm AA machine cannon. It was introduced in 1944 and approximately 500 to 616 guns were produced.^[1][2][3] It was mainly designed for use against ground targets, but was only used in an anti-aircraft role.^[4]

Type 4 20mm twin AA machine cannon
Type	Autocannon
Place of origin	Empire of Japan
Service history
In service	1944–1945[1]
Used by	Japan
Wars	World War II
Production history
No. built	approximately 500[1] (an alternate source states 616 units produced[2])
Specifications
Barrel length	1.4 m (4 ft 7 in) L/70[3]
Shell	20×142 mm[3]
Caliber	20 mm (0.79 in)[3]
Action	Gas operated
Rate of fire	600 rounds/min (maximum)
Muzzle velocity	950 m/s[3]
Maximum firing range	5,500 m (18,000 ft) (horizontal) 3,500 m (11,500 ft) (altitude)[3]
Feed system	2x 20 round box

The Type 98 20 mm AA machine cannon was the most common light anti-aircraft gun of the Japanese military and the IJA used it until the end of World War II.^[3][5]