There were approximately 1,100 Model 1855 shotguns made in total. However, the .60 caliber revolving shotgun was based on the far more common .56 caliber military rifle frame, while these 10 gauge shotguns has their own special large frame size really making them their own special model. This frame is the largest frame size of the Model 1855 Sidehammer Revolving long arm series. Per R.L. Wilson on page 201 of "The Book of Colt Firearms," only 600 of these rare large frame 10 gauge (.75 caliber) revolving shotguns were manufactured. Their survival rate is also low, making these shotguns, especially in high condition like this one, exceedingly scarce. By some estimates, only 50-100 of these shotguns are known today, making them rarer than the famous Colt Walker and among the rarest of all antique Colts. Like the Model 1855 rifles, these rare shotguns would have seen use in the American West and Civil War, and Model 1855s also saw use overseas, including by Australian outlaw Ned Kelly. It has a bead front sight, top strap groove that acts as a rear sight, "COL. COLT HARTFORD CT. U.S.A." marked on the top strap, "PATENTED SEPT 10th 1850" marked in one of the cylinder flutes, "COLT'S PATENT/Nov. 24th 1857" on the right side of the frame, the serial number on the bottom of the frame, the large scroll trigger guard, short forend with brass nose cap and German silver wedge escutcheons, and a deluxe checkered buttstock with attractive figure, flat shotgun buttplate numbered to the gun, brass cleaning rod in the stock compartment, and 14 1/2 inch length of pull. This incredible example is pictured as number 12 on page 78 of “The Stagecoach Museum Gun Collection" book. It was subsequently owned by the late Texas collector Robert Howard. Provenance: The Stagecoach Museum Collection; The Robert Howard Collection; Property of a Gentleman