Ho-401 cannon

Ho-401 was a Japanese aircraft autocannon that saw limited, if any, use during World War II. It was a large-caliber version of the 37 mm Ho-203 cannon. The cannon was used on the ground-attack, Kawasaki Ki-102b heavy fighter of the Imperial Japanese Army Air Force.

Specifications

 * Caliber: 57 mm (2.25 in)
 * Ammunition: 57 x 121R (1,550 g)
 * Weight: 150 kg (330 lb)
 * Rate of fire: 80 rounds/min
 * Muzzle velocity: 495 m/s (1,624 ft/s)