A .50-caliber breech-loading percussion carbine, with 21.75" round barrel having an octagonal breech. Blued case-hardened, with walnut stock. Barrel marked "Address/Poultney & Trimble/Baltimore, USA" and frame "Smith's Patent/June 23, 1857" as well as "American Arms Co./Chicopee Falls". Approximately 30,000 manufactured, most of which were purchased by the United States government. Sales agents were Poultney & Trimble of Baltimore, Maryland.