Colt small frame Model 1855 Revolving Shotgun manufactured between 1860 and 1863. The shotgun has a .60 caliber (20 gauge) round barrel with semi-octagonal section at the breech. The barrel has an under-rib with two ramrod pipes and is fitted with a brass front sight bead at the muzzle. The shotgun has a wooden ramrod with flared, brass, tip. The shotgun has a five-shot fluted cylinder, straight rammer with indented center, small frame with sighting grove on the top strap and round iron trigger guard. The walnut stock has an iron, shotgun buttplate. The wedge-fastened forearm has a German silver forearm tip and oval wedge escutcheon. The stock and forearm are straight grain walnut with a varnish finish. The top of the octagonal section of the barrel is roll-stamped: "{COLT'S PT./1856}" in two lines followed by "{ADDRESS COL. COLT/HARTFORD CT. U.S.A.} in two lines. The left side of the frame is roll-stamped: "COLT'S PATENT/Nov.24th 1857" in two lines. "PATENTED SEPT. 10th 1850" is stamped in one cylinder flute. The serial number, "223", is stamped on the underside of the frame, the trigger guard finial and on the toe of the buttplate. All of the visible serial numbers match. An oval cartouche with illegible markings is stamped on the underside of the stock behind the trigger guard. The Colt Model 1855 Revolving Shotgun was manufactured in limited numbers; total production was approximately 1100 guns between 1860 and 1863. The estimated production of small frame (20 gauge) Model 1855 Shotgun is 500 guns.