[citation needed] 12 cwt referred to the weight of the barrel and breech - 1,344 lb (610 kg) - to differentiate it from other 12-pounder guns.

Hence in 1914 when Germany occupied parts of Belgium and northern France, it faced the risk of air attack, and various medium caliber guns were adapted to high-angle mountings, including the 12 pdr 12 cwt.

For anti-aircraft firing, Fixed QF rounds were quickly developed i.e. with the shell already attached to the cartridge case.

Comparison:[3]- At the end of World War I, 36 guns were still in service in the home air defense of Britain, 10 on the Western Front and 2 in Mesopotamia where it was typically mounted on river barges.

[6] The gun remained in Royal Navy anti-aircraft use, in the form of the new Mk V version, on smaller ships in World War II because of its low and high angle firing.