The Colt Model 1851 Navy series was the second most popular Colt percussion revolver manufactured and was the most widely used Colt revolver by the U.S. military. They were also purchased for use by the British Navy. Due to the Model 1851's long production run, there are an incredible number of variations. This has made them among the most popular of all Colt firearms with collectors. This 1851 Navy was manufactured in 1856 near the end of the Navy-Navy range. It has an iron grip frame as was standard for the Navy-Navy revolvers, and is marked with "-ADDRESS SAML COLT NEW-YORK CITY-" on the barrel, "COLTS/PATENT/U.S." on the left side of the frame, the Texas Navy cylinder scene, and matching visible serial numbers. The butt is marked with "TMA" on the grip to the right, but the bottom of the back strap lacks the usual U.S. Navy marking and no inspection marks are visible throughout. It has a brass cone front sight, hammer notch rear sight, and smooth walnut grip. Note that it lacks the capping groove; this is often seen on early revolvers purchased for the Navy. Not all Navy-Navy revolvers received inspection and Navy property markings. They may have also been removed in period. 1851 Navy expert Nathan Swayze theorized that the iron back straps were manufactured due to a preference for "black mountings" in Britain. Many were then sent back the U.S. and used on Hartford production revolvers as is the case on this example based on the large groove in the back strap behind the hammer.