This is a nice example of the Colt 1871-72 Open Top Revolver in .44 Rimfire. This was Colt's very first production cartridge revolver introduced following the long-awaited expiration of 1857 Rollin White Patent on bored-through cylinders. This patent was purchased by Smith & Wesson, a shrewd move which gave the firm a 14 year head-start on their competition minus a few infringements during the Civil War that landed in court...all in S&W's favor of course. This left S&W's main competitor, Colt essentially stuck in the percussion revolver business until 1871. The Company sure made up for lost time rather quickly with the introduction of the Open Top in .44 Rimfire with 7,000 units produced before introducing the famous Model 1873 Single Action Army. During the 1870's, Colt also converted many of its unsold percussion models into cartridge guns however, while sharing some of the basic design and components, the Model 1871-72 was actually its own independent design and not a conversion...which I understand to be a somewhat popular misconception. At any rate, this Model is not the easiest to find in great shape as many went to the American Frontier where they were used quite hard.
Serial number is in the 1500 range with nearly all matching numbers which include the frame, barrel, tg, bs, cylinder, wedge, even the grips are the originals and numbered to the gun. The sole with EXCEPTION is the arbor pin which is a different number. The left side of the frame is marked with the 1871 and 1872 patent dates, the same ones used on the Colt SAA up through today. If you ever get bored and want to read up on these patent dates, you'll find them in a the patent libraries of Technical Universities or in Part 4 of "A History of the Colt Revolver" by Haven and Belden. 1940. The 1871 Patent is number 117461 and pertains mainly to 4 alterations of percussion guns to cartridge...I believe the one item that pertains to the Open Top deals with ejector housing's design to retain the ejector rod. The 1872 patent date, No. 128,644, also has to do with the ejector housing. There barrel address is clearly marked "-ADDRESS COL SAML COLT NEW-YORK U.S. AMERICA-".
Overall condition is NRA Antique Good+ with nice smooth grey metal with a pleasing patina. You can still discern some remnants of mottled case colors on the frame and traces of original blue on the backstrap. Cylinder shows 60% original cylinder scene that's thinning. The brass trigger guard shows no signs of original silver plating on the outside but upon inspection of the grips, found quite a bit internally. Grips are original to the gun although slightly undersized from light cleaning but fit tight up to all the metal surfaces. No awkward gaps. There are a couple of minor chips in the corners (next to the frame) that have been masterfully repaired..so well that they're hardly perceptible. Hammer has nice sharp checkering. Action is crisp and in excellent working order. Bore is exceptionally nice for a black powder-era weapon in Fine+ to Excellent condition. Still bright with strong lands and grooves with a few light pits. A nice representative example of a scarce Colt 1871-72 Open Top.