Enfield revolver The Enfield Revolver was a self - extracting British handgun designed and manufactured at the government - owned Royal Small Arms Factory in Enfield ; initially in the . 476 calibre ( actually 11 . 6 mm ) The . 476 calibre Enfield Mk I and Mk II revolver s were the official sidearm of both the British Army and the North - West Mounted Police , as well as being issued to many other Colonial units throughout the British Empire The term " Enfield Revolver " is not applied to Webley Mk VI revolvers built by RSAF Enfield between 1923 and 1926 . The Enfield No . 2 is an unrelated . 38 calibre revolver that was the standard sidearm of British and Commonwealth forces during World War II . Enfield Mk I & Mk II Revolvers . The first models of Enfield revolver — the Mark I and Mark II — were official British military sidearms from 1880 through 1887 , and issue sidearms of the North - West Mounted Police in Canada from 1883 until 1911 . NWMP Commissioner Acheson G . Irvine ordered 200 Mark IIs in 1882 , priced at C $ 15 . 75 each , which were shipped by London ' s Montgomery and Workman in November that year , arriving in December . They replaced the Adams . Irvine liked them so much , in one of his final acts as Commissioner , he ordered another 600 , which were delivered in September 1885 ; his replacement , Lawrence W . Herchmer , reported the force was entirely outfitted with Enfields ( in all 1 , 079 were provided ) and was pleased with them , but concerned about the . 476 round being too potent . The first batch was stamped " NWMP - CANADA " ( issue number between ) after delivery ; later purchases were not . They were top - break single - or double - action , and fitted with lanyard rings . Worn spindle arms would fail to hold empty cases on ejection , and worn pivot pins could cause barrels to become loose , resulting in inaccuracy . Its deep rifling would allow firing of slugs of between diameter . Complaints began arising as early as 1887 , influenced in part by the British switching to Webley s , and by 1896 , hinge wear and barrel loosening were a real issue . Beginning in late 1904 , the Mark II began to be phased out in favor of the . 45 calibre Colt New Service revolver , but the Enfield remained in service until 1911 . The . 476 Enfield cartridge the Enfield Mk I / Mk II were chambered for fired a lead bullet , loaded with of black powder . The cartridge was , however , found to be somewhat underpowered during the Afghan War and other contemporary Colonial conflicts , lacking the stopping power believed necessary for military use at the time . Unlike most other self - extracting revolvers ( such as the Webley service revolvers or the Smith & Wesson No . 3 Revolver ) , the Enfield Mk I / Mk II was somewhat complicated to unload , having an Owen Jones selective extraction / ejection system which was supposed to allow the firer to eject spent cartridges , whilst retaining live rounds in the cylinder . The Enfield Mk I / Mk II had a hinged frame , and when the barrel was unlatched , the cylinder would move forward , operating the extraction system and allowing the spent cartridges to simply fall out . The idea was that the cylinder moved forward far enough to permit fired cases to be completely extracted ( and ejected by gravity ) , but not far enough to permit live cartridges ( i . e . , those with projectiles still present , and thus longer in overall length ) from being removed in the same manner . The system was obsolete as soon as the Enfield Mk I was introduced , especially as it required reloading one round at a time via a gate in the side ( much like the Colt Single Action Army or the Nagant M1895 revolvers ) . Combined with the somewhat cumbersome nature of the revolver , and a tendency for the action to foul or jam when extracting cartridges , the Enfield Mk I / Mk II revolvers were never popular and eventually replaced in 1889 by the . 455 calibre Webley Mk I revolver .