20 mm Polsten
| Polsten | |
|---|---|
A Canadian towed anti-aircraft mounting featuring three Polsten cannons. | |
| Type | Autocannon |
| Place of origin | Poland United Kingdom |
| Service history | |
| In service | 1944 - 1950s |
| Production history | |
| Designed | 1939-1941? |
| Manufacturer | John Inglis |
| Unit cost | £60 - £70 |
| Specifications | |
| Mass | 57 kg (126 lb) |
| Length | 2.1 m (6 ft 11 in) |
| Barrel length | 1.45 m (4 ft 9 in) (barrel) |
| Calibre | 20 mm (0.78 in) |
| Action | API blowback |
| Rate of fire | 450 rpm |
| Muzzle velocity | 830 m/s (2,700 ft/s) |
| Effective firing range | 1,000 m (3,281 ft) |
| Maximum firing range | 2,000 m (6,562 ft) |
| Feed system | 60 round drum magazine or 30 round box magazine |
The Polsten was a Polish development of the 20 mm Oerlikon gun. The Polsten was designed to be simpler and much cheaper to build than the Oerlikon, without reducing effectiveness.