Total production of these U.S. Richards conversions is estimated at around 1,200, and any example in high condition is very hard to find, especially the exceptionally scarce U.S. contract revolvers like this one. These conversions are important pieces in the evolution of Colt firearms and bridge the gap between the iconic percussion revolvers that established Colt as the name associated with revolvers and the Single Action Army revolver that became the most iconic handgun in history. The Richards conversion was patented by Assistant Superintendent Charles Brinckerhoff Richards at Colt in July 1871. He also patented the design for the Colt Cloverleaf House Model that same year and worked alongside William Mason, the superintendent, in designing the famous Single Action Army. This revolver has the mixed numbers and government inspection markings associated with the Richards conversion revolvers for the U.S. government. This exact revolver is pictured on page 140 of "The William M. Locke Collection" by Frank Sellers (incorrectly listed as a Richards-Mason). Existing revolvers from multiple government arsenals were shipped back to Colt for these conversions. The conversion consisted of shaving 3/16 of an inch off of the recoil shield to accommodate the installation of the Richards breech plate which has an integral notch rear sight, a loading gate, and a rebounding firing pin. The recoil shield was also machined to provide a straight channel for the loading and ejecting of cartridges. The hammer was ground flat to properly strike the firing pin. The barrel was machined to accept the Richards ejector assembly which is secured by a screw and an extension that fills in the original loading lever channel. This example has the standard First Model Richards Conversion loading gate that has an internal coil spring and features a German silver blade front sight, "-ADDRESS COL. SAML COLT NEW-YORK U.S. AMERICA-" on top of the barrel, "US" by the wedge screw, standard "COLTS/PATENT" marking on the frame which was originally cut for use with a shoulder stock, naval battle roll scene and "AP" marking on the cylinder, "A" and "H" sub-inspection marks on the trigger guard, "G" and "6" near the toe of the front strap on the left, recoil shield/breech plate with integral notch rear sight, borderless knurling on the hammer spur, "T" sub-inspection mark on the top of the back strap, and a smooth walnut grip with Orville W. Ainsworth cartouche. Ainsworth also famously inspected the first Single Action Army revolvers which included those issued to Custer's 7th Cavalry, and these conversion revolvers were also used in the Indian Wars of the post-Civil War era. Matching conversion serial numbers "78" are marked on the ejector, barrel (twice), wedge, cylinder, frame, and trigger guard. The other numbers are: "84599" on the barrel, "1950" on the cylinder pin, "57590" on the trigger guard, "118760/332" on the back strap, "70" on the recoil shield and loading gate, and "332" in the replacement back strap inlet of the grip. The original serial number on the frame was removed when the frame was converted and refurbished, but faint traces of it can be seen upon close inspection. The conversion assembly number was stamped directly on the location of the original number. Those revolvers that retained original serial numbers had the assembly number shifted below.

Exceptionally fine as arsenal refurbished overall with 80% casehardened finish which retains vibrant colors, 85% plus blue finish, light muzzle and edge wear, patches of light gray and brown patina and some slight oxidation, the vast majority of the rich niter blue on the trigger, 90% plus silver plating on the trigger guard/front strap with mild fading at the edges and light aged patina, and some scattered light scratches and marks. The grip is fine and has a partially faded but clearly legible cartouche, minor edge wear, and some minor scratches and dings. It remains mechanically excellent. This is easily one of the finest U.S. Contract First Model Richards Conversion Colt Model 1860 Army revolvers in existence and should be destined for a prized position in one of the finest collections of Colt firearms as it already has been before.