Hispano-Suiza HS.820
| HS.820 | |
|---|---|
Swiss HS.820 in the HS.666A configuration. | |
| Type | Autocannon |
| Place of origin | Swiss |
| Specifications | |
| Mass | 66 kg (146 lb) (without ammunition) |
| Length | 2,489 mm (98.0 in) |
| Barrel length | 1,727 mm (68.0 in) |
| Caliber | 20×139 mm |
| Action | Gas unlocked, delayed blowback |
| Rate of fire | 1000 round/min |
| Muzzle velocity | 1,050 m/s (3,400 ft/s) |
| Effective firing range | 1,500 m (4,900 ft) against aerial targets |
The HS.820 is a 20 mm caliber autocannon developed by Hispano-Suiza primarily for aircraft use, but more widely used in a series of ground-based anti-aircraft guns. After Oerlikon purchased Hispano's armaments division in 1970, the HS.820 became the Oerlikon KAD, supplanting Oerlikon's own KAA and KAB weapons in the process. A US-built model, the M139, was used on the M114A1E1 and M114A2 Armored Command & Reconnaissance Carrier.