Produced by Bristol. Chambered for .54-caliber. Breech-loader that uses percussion ignition system, but features a cartridge of sorts made of copper and a tape priming device that was located inside frame. Has 22" round barrel, with no fore-end, walnut stock and inspector's cartouche. Finish blued and case colored. Frame stamped "Burnside's /Patent/March 25th/1856". Approximately 250 1st Models manufactured.