QF 12-pounder 18 cwt naval gun

Ordnance QF 12-pounder 18 cwt
Deployed as anti-aircraft gun on HMS Agamemnon off Salonika, 1916
TypeNaval gun, Coastal defence
Place of originUnited Kingdom
Service history
In service1906–1921?
Used byRoyal Navy
WarsWorld War I
Production history
DesignerElswick Ordnance Company
Designed189?
Specifications
MassGun & breech: 2,016 lb (914 kg)
Barrel lengthBore: 150-inch (3.81 m) (50 calibres)

ShellSeparate QF 12.5 lb (5.66 kg)
Calibre3 in (76 mm)
Rate of fire20 rd/min
Muzzle velocity2,600 ft/s (790 m/s)
Effective firing range9,300 yards @ +20°
(8,500 m @ +20°)

The QF 12 pounder 18 cwt gun (Quick-Firing) was a 3-inch high-velocity naval gun used to equip larger British warships such as battleships for defence against torpedo boats. 18 cwt referred to the weight of gun and breech (18 × 112 lb = 2,016 lb or 914 kg), to differentiate the gun from others that also fired the "12 pound" (actually 12.5 lb or 5.7 kg) shell.