Oerlikon KA series 20mm cannon

• Name — Oerlikon GAI-BO1 • Origin — Switzerland • Type — Anti-aircraft gun Autocannon • Is Ranged — yes • Is Artillery — yes • Used By — Argentina Austria Nigeria South Africa Spain Switzerland Afghanistan • Wars — Cold War • Designer — Oerlikon • Design Date — 1950s • Manufacturer — Oerlikon • Weight — 405 kg • Length — 3.8 m • Part Length — 2.4 m • Width — 1.5 m • Height — 2.5 m • Crew — 2 • Cartridge — Fixed QF 20×128 mm • Cartridge Weight —.125 kg • Caliber — 20 mm • Action — Gas • Rate — 1,000 rpm (cyclic) • Velocity — 1100 m/s • Range — AA: 2 km Ground: 1.5 km • Max Range — AA: 4.5 km Ground: 5.7 km • Feed — 8-round magazine 20-round magazine 50-round magazine • Sights — 1× aerial targets 3.5× ground targets • Carriage — Two wheeled carriage with three folding outriggers • Elevation — -5° to +85° • Traverse — 360°

The GAI-BO1 consists of a KAB 20×128 mm auto-cannon mounted on a folding platform. The gun has no power assistance with elevation of the counter-balanced barrel controlled by a hand-wheel and traverse is by foot. Due to its lack of power assistance it is unable to engage fast moving aerial targets, although it is still useful for engaging light observation aircraft and helicopters. Three different sized magazines (8-round, 20-round and 50-rounds) are available. There is a simple mechanical computing sight with 1× magnification for aerial targets and a 3.5× scope for engaging ground targets. In its ground role it can fire armor-piercing rounds capable of piercing 15 mm of rolled homogeneous armor at 600 m.