Manufactured in 1851 under U.S. contract, this Colt Second Model Dragoon revolver was later issued to the Commonwealth of Massachusetts under the Militia Act and stamped "MS" in front of the trigger guard. According to the 2013 publication "Massachusetts Marked Colt Second Model Dragoon Revolvers Their Early History and U.S. Civil War Issue" by Douglas L. Hays, Jr. only 100 Colt Second Model Dragoons were procured from the U.S. Ordnance Department by the Massachusetts Militia in 1852. Hays estimates approximately 20 "MS" marked Second Model Dragoons are known to exist today. The serial numbers are scattered randomly and span a numerical range of 450, mostly in the 10000-11000 range. The revolver has the distinctive combination of rectangular cylinder stops and square-back brass trigger guard that identify Second Model Dragoon revolvers. The top of the barrel is roll-stamped: "-ADDRESS SAML COLT NEW-YORK CITY-". "COLT'S/PATENT/U.S." is roll-stamped in three lines on the left side of the frame. The cylinder is roll-engraved with the Ranger and Indian fight scene and "MODEL U.S.M.R./COLT'S PATENT". Single letter government inspection marks are visible on various parts and the grip is marked with boxed "W.A.T." cartouches. The full serial number, "10612", is stamped on the barrel lug, frame, trigger guard, back strap and cylinder. The partial serial number "0612" is stamped on the lever. "612" is stamped on the cylinder pin and wedge. Colt manufactured fewer Second Model Dragoon revolvers (2,700) than any other Dragoon revolver, making them relatively scarce, even more-so with Massachusetts militia markings!