Colt 45

The Colt 45

Bound by the Rollin White patent (#12,648, April 3, 1855) and not wanting to pay a royalty fee to Smith & Wesson, Colt could not begin development of bored-through revolver cylinders for metallic cartridge use until April 4, 1869. The Colt Single Action Army was designed for the US government service revolver trials of 1873 by Colt's Patent Firearms Manufacturing Company and adopted as the standard military service revolver. Its original moniker was the "New Model Army Metallic Cartridge Revolving Pistol".


The very first production Single Action Army, serial number 1, thought lost for many years after its production, was found in a barn in Nashua, New Hampshire in the early 1900s.

The .45 Colt cartridge was of center fire design containing charges of up to 40 grains (2.6 g) of fine grained black powder and a 255-grain (16.5 g) blunt round nosed bullet. Relative to period cartridges and most later handgun rounds, it was quite powerful in its full loading.


The Colt Single Action Army revolver (along with the 1870 and 1875 Smith and Wesson Model 3 ("Schofield") revolvers) replaced the Colt 1860 Army Percussion revolver. The Colt quickly gained favor over the S&W and remained the primary US military sidearm until 1892 when it was replaced by the .38 Long Colt caliber Colt Model 1892, a double action revolver with swing-out cylinder. By the end of 1874, serial no. 16,000 was reached; 12,500 Colt Single Action Army revolvers chambered for the .45 Colt cartridge had entered service and the remaining revolvers were sold in the civil market.

The Single Action Army became available in standard barrel lengths of 4¾", 5½" as well as the Cavalry standard, original 7½". The shorter barreled revolvers are sometimes called the "Civilian" or "Gunfighter" model (4¾") and the Artillery Model (5½"). There was also a variant with a sub 4" barrel, without an ejector rod unofficially referred to as the "Sheriff's Model", "Banker's Special", or "Storekeeper"

From 1875 until 1880 Colt marketed a Single Action revolver in the .44 rimfire Henry caliber in a separate number range from no. 1 to 1,863.

A "Flattop Target Model" was listed in Colt's catalogs from 1890 to 1898. Colt manufactured 914 of these revolvers with a frame which was flat on the top and fitted with an adjustable leaf rear sight. The front sight consisted of a base with a interchangeable blade.


In 1896, at serial number 164,100, a springloaded base pin latch replaced the cylinder pin retaining screw and by 1900, at serial number 192,000, the Colt Single Action was certified for use with smokeless powder.  In 1920, larger, highly visible sights replaced the original thin blade and notch. The revolvers remained essentially unchanged from that point until cessation of manufacture at the beginning of World War II.

All original, good condition, U.S. Cavalry and Artillery Single Action Armies (those produced between 1873 and 1891) are among the most valuable to the collector. Especially valuable, often going for well over $10,000, are the OWA (Orville Wood Ainsworth) and the rare Henry Nettleton inspected Single Action Army Colts. The OWA Colt refers to the earliest issued Single Action Army guns which were inspected by Orville W. Ainsworth. Ainsworth was the ordnance sub-inspector at the Colt factory for the first 13 months (Oct. 1873 to Nov. 1874) of the Single Action Army's production. It was Ainsworth who inspected the Colts used by Col. G.A. Custer's 7th Cavalry at the Battle of the Little Bighorn. The number range of possible Little Bighorn Colts is 4500 - 7527.