QF 12-pounder 8-cwt Mk I naval gun

The QF 12-pounder 8-cwt Mk I naval gun was a 3 in calibre gun used by the Royal Navy. In British service, "12 pounder" was a rounded reference to the projectile weight and "12 cwt" referred to the weight of the barrel and breech : 8 hundredweight = 8 x 112 pounds = 896 pounds, to differentiate it from other "12-pounder" guns.

It was primarily used to equip boats and for landing parties as well as for the. Fourteen were converted into anti-aircraft guns as Mk I*.