The Colt Revolving Rifle of 1855 - aptly named the "Model 1855" - was an attempt to provide the repeating action of a revolver within a shortened rifle form ("carbine"). Carbines were typically shortened-barrel forms of longer rifle counterparts and were suitable for use by mounted troops or second-line infantry (while also being a firearms category still in use today). The Model 1855 brought all of these qualities together in a handy, albeit less-than-perfect, design under the Colt product brand.
The Model 1855 arrived in three distinct caliber forms: .36, the .44 and .56. Additionally, the rifle could be purchased in four barrel lengths: 15-, 18-, 21- and 24-inches. If the selected caliber was the .36 or the .44, a six-shot cylinder was included while chambering for .56, restricted the gun to a five-shot cylinder. Regardless, combining the repeating action of a revolver, the accuracy of a rifle, and an ammunition supply greater than that of any musket of the day, the operator of a Model 1855 held a distinct advantage in a gunfight.
Externally, the Model 1855 was a departure from the rifle-muskets then in use and more of a glimpse into the world of long guns that made up the "Wild West". The carbine sported a rounded barrel set within a metal framework for durability. The cylinder was fluted and set within a closed-frame design. The firing action was of percussion and operated via a hammer fitted along the right side of the gun's body. The trigger was set under the rifle-style hand grip and protected within an elegant oval trigger ring. The wooden stock was curved at the butt to accept the shoulder when firing. In all, the Model 1855 was an elegant design combining metal and wood and offering clean lines typical of Colt products of the day.
The Model 1855 was adopted by the U.S. Army in 1855 but full-scale use would not come until 1857 due to issues with "cook off" of the chambered ammunition. After firing of a cartridge, a great deal of hot gas was generated in and around the ammunition cylinder and this settled in the various parts of the chamber. As gunpowder was, of course, subject to igniting under such heated conditions this residual gas could make its way into the remaining chambered rounds, effectively setting those rounds off in an unintentional manner. The rounds would fire straight out of the cylinder itself, hitting whatever lay before them as if triggered by the hammer/cap arrangement. This action could injure the support arm of the operator or anyone unlucky enough to find themselves near the forward sections of the gun. This defect ultimately earned the carbine a less-than-stellar reputation.
The cook-off issue was so apparent that special instruction was given to shooters. This included using the weapon with only a single round chambered, defeating the purpose of five or six ready-to-fire chambered rounds. Another suggestion involved the operator holding the weapon with his supporting hand close to the trigger group and out of the reach and path of any misfiring rounds. It would seem that the Model 1855 could be as dangerous to its user as it was to a given target.
Regardless, the weapon's use persisted and sources state some 4,435 to 4,712 rifles were purchased by the American government for use during the Civil War. The capacious ammunition supply no doubt added much needed repeat firepower for Federal forces and proved quite deadly in skilled hands - the weapon certainly earned the respect of Confederate soldiers despite the weapons limited production. Well known actions involving the Model 1855 included the Battle of Chickamauga fought from September 19th until September 20th, 1863. Versions fitted with over-receiver scopes could be used in the sharpshooter role with deadly effectiveness.
The success on the field did not directly relate to success in the general market for Colt. The revolving rifle's safety was reevaluated by U.S. authorities to which a group decided against keeping the weapon in the Army inventory or adding to the existing stocks. The rifle was therefore dropped from service and many examples were sold off at what were then bargain prices. Such ended the legacy of the Colt Model 1855 "Revolving Rifle". Its 4,400-plus production total, and its use in the Civil War do make this carbine a very rare and special firearm to obtain today.