The Sharps military rifle
1863 Sharps Carbine
Very popular with cavalry on both sides (less so than the 7-shot Spencer carbine, however, and far more common than the field rifle version) the single-shot Sharps carbine was a lightened and shortened version of the rifle. The brevity of the "falling block" mechanism allowed a correct barrel length, therefore a less strong detonation and recoil and a fairly good accuracy. In addition, the problem of the primer (difficult to take from a pouch and to place on the chimney when you are on horseback, especially with gloves...) was solved by a technical characteristic of the Sharps, an "automatic" primer:a primer was pushed out of a receptacle located against the case and placed on the funnel each time the shooter cocked the hammer.
The Sharps carbine was very simply transformed after the Civil War to be able to use the new metal cartridge with central percussion .45-70 Gvt. It was then much more reliable than the transformed Springfields with their "trap-door" mechanism (cellar door), hence their great popularity during the Indian Wars of the late 19th century