[4] It was produced by Armstrong Whitworth, Elswick and used on Royal Navy warships, exported to allied countries, and used for land service.

As the Type 41 3-inch (7.62 cm)/40 it was used on most early battleships and cruisers of the Imperial Japanese Navy, though it was commonly referred to by its UK designation as a "12-pounder" gun.

Mk I and II guns, of "built up" construction of steel layers, served on many Royal Navy destroyers up to and after World War I originally as primary and later as secondary armament against submarines and torpedo boats.

Among other guns, 16 QF 12-pounder 12 cwt were landed from warships and were mounted on improvised field carriages designed by Captain Percy Scott RN, with solid wooden trails and utilizing small-diameter Cape wagon wheels.

[7] Lieutenant Burne reported that the original electric firing system, while working well under ideal conditions, required support of an armourer and the maintenance and transport of charged batteries in the field, which was generally not possible.

Perhaps uniquely, the guns were refused by the War Office and donated directly to Lord Roberts, the British commander in South Africa and became his personal property.

[9] Many guns were mounted on "pedestals" secured to the ground to defend harbours around the UK, and at many ports around the Empire, against possible attack by small fast vessels such as torpedo boats, until the 1950s.

UK shells weighed 12.5 lb (5.67 kg) filled and fuzed.The cordite propellant charge was normally ignited by an electrically activated primer (in the base of the cartridge case), with power provided by a battery.