| Ordnance QF 1½ pdr Mk III | |
|---|---|
| Type | Autocannon |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1918 - 1940s |
| Used by | United Kingdom |
| Production history | |
| Designer | Coventry Ordnance Works |
| Manufacturer | Coventry Ordnance Works |
| Variants | Mk III, Mk IV |
| Specifications | |
| Mass | 200 pounds (91 kg) for cradle, gun & breech[1] |
| Length | 91.8 inches (2.33 m) total |
| Barrel length | bore of 75 inches (1.9 m)[1] |
| Shell | 37x190R HE 1 lb 7 oz (0.65 kg) or armour-piercing |
| Calibre | 37 mm (1.457 in) |
| Barrels | 1 |
| Action | automatic, long recoil [2] |
| Rate of fire | 90 rpm |
| Muzzle velocity | 1,950 ft/s[1] |
| Effective firing range | 4,500 yd (4.1 km)[3] |
| Feed system | 5 round clip |
The COW 37 mm gun was a British automatic cannon that was developed during First World War as a large-calibre aircraft weapon. It was tested in several installations and specified for the Westland C.O.W. Gun Fighter for attacking bombers. The tests did not yield satisfactory results and the weapon did not enter general service except on a few flying boats. The design was later adapted as the basis of the Vickers S, which saw some service during the Second World War as an anti-armour weapon.