| Ho-401 cannon | |
| Origin: | Imperial Japanese army |
| Type: | Aircraft cannon |
| Is Ranged: | yes |
| Is Uk: | yes |
| Weight: | 150kg (330lb) |
| Length: | 2000mm |
| Part Length: | 800mm |
| Cartridge: | 57 x 121R (1,550 g) |
| Caliber: | 57mm |
| Action: | Short recoil-operated |
| Rate: | 80 rounds/min |
| Velocity: | 495m/s |
| Feed: | 16-round drum |
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.[1]