Colt New Service The Colt New Service was a double - action revolver made by Colt from 1898 until c . 1940 . It was adopted by the U . S . Armed Forces in . 45 Colt as the Model 1909 U . S . Army , Marine Corps Model 1909 , Model 1909 U . S . Navy and in . 45 ACP as the Model 1917 U . S . Army . The Model 1917 was created to supplement insufficient stocks of M1911 pistols during World War I and was dropped from production in 1941 . History . Colt M1917 revolver . Colt had produced a revolver for the U . S . Army called the M1909 , a version of their heavy - frame , . 45 - caliber , New Service model in . 45 Long Colt to supplement and replace a range of 1890s - era . 38 caliber Colt and Smith & Wesson revolvers that had demonstrated inadequate stopping power during the Philippine – American War . The Colt M1917 Revolver was a New Service with a cylinder bored to take the . 45 ACP cartridge and the half - moon clips to hold the rimless cartridges in position . Later production Colt M1917 revolvers had headspacing machined into the cylinder chambers , just as the Smith & Wesson M1917 revolvers had from the start . Newer Colt production could be fired without the half - moon clips , but the empty cartridge cases had to be ejected with a device such as a cleaning rod or pencil , as the cylinder extractor and ejector would pass over the rims of the rimless cartridges . During its lifetime , the Colt New Service was the most popular revolver made by Colt , surpassing 150 , 000 units . After World War I , the revolver gained a strong following among civilian shooters . Fitz Special . John Henry Fitzgerald was an employee of Colt prior to World War II and was known to carry of a pair of New Service " Fitz Specials " in his front pockets . These revolvers had bobbed hammers , 2 " barrels , shortened and rounded grip frames , and the front of the trigger guard was removed . Although less than 30 left the factory , it became an after - market conversion for many gunsmiths . Colonels Rex Applegate and Charles Askins were proponents of this model . Canada and United Kingdom . In 1899 Canada acquired a number of New Service revolvers ( chambered in . 45 Colt ) for Boer War service , to supplement its existing Model 1878 Colt Double Action revolvers in the same caliber . In 1904 / 5 the North - West Mounted Police in Canada also adopted the Colt New Service to replace the less - than satisfactory Enfield Mk II revolver in service since 1882 . New Service revolvers , designated as Pistol , Colt , . 455 - inch 5 . 5 - inch barrel Mk . I , chambered for the . 455 Webley cartridge were acquired for issue as " substitute standard " by the British War Department during World War I . British Empire Colt New Service Revolvers were stamped " " NEW SERVICE . 455 ELEY " " on the barrel , to differentiate them from the . 45 Colt versions used by the US ( and Canada ) . The Colt New Service was a popular revolver with British officers , and many of them had privately purchased their own Colt New Service revolvers in the years prior to World War I as an alternative to the standard - issue Webley Revolver . 60 , 000 Colt New Service revolvers were supplied to British Empire and Canadian forces during World War I , and they continued to see official service with US until the end of World War II .