The Model 1912 Mark II Royal Horse Artillery,
The semi automatic line of pistols introduced by Webley and Scott during the early 20th century. The British military took little notice of the pistol, instead preferring to issue revolvers instead. However there were a few exceptions. The Model 1912 Mark I was adopted by the Royal Navy and used in limited amounts during World War I. Also during World War I, a strange pistol carbine was adopted by the Royal Horse Artillery Regiments called the Model 1912 Mark II.
The Model 1912 Mark II was adopted by the Royal Horse Artillery because of its lightness and compact size. With its detachable stock the weapon could be holstered like a pistol, but in a time of emergency be used like a long arm. During World War I pistol carbines were quite popular with artillery units because of this feature, which allowed artillerymen to work their big guns without hindrance, yet still defend themselves if attacked by the enemy. The Webley Model 1912 Mark I and Mark II was chambered in an automatic form of the old .455 Webley, which was called the .455 Webley Auto. In terms of dimensions and performance it was similar to the .45 ACP.
Later in the war, the Webley Model 1912 Mark II was also adopted by the Royal Flying Corps.