During the American Civil War in 1863, James Warner was granted a patent for a new breech-loading, cartridge-based firearm that became known as the Warner Carbine. The design took on a conventional arrangement and was chambered for the .50 rimfire cartridge. A wooden stock and forend bookended the brass receiver which enclosed the working systems of the gun. The trigger unit was underslung in the usual way. The barrel was of 20-inch length and set ahead of the action. Its length was such that only a single band joined it at the stock. This design was handed to the Massachusetts Arms Company to fulfill a production contract in 1864 - the war's final full year.
The carbine proved itself a reliable and effective man-stopping system for its short exposure in the war. A hinge allowed access to the breech for loading / reloading of cartridges and the spent cartridges themselves were extracted by way of a slide at the forend. These qualities made for a very modern weapon for its time - though the carbine was still limited to single shots which could prove a liability in combat.
Due to the end of the war, only about 1,500 of these carbines were completed.