.22RF. 10" octagon to round barrel. NSN. Blued and color casehardened finish, smooth varnished walnut grip and forend. Single shot .22 rimfire alteration of a US M1867 Naval Rolling Block Pistol with added semi-buckhorn elevation adjustable rear sight and dovetailed tall-blade front sight. Barrel with one-line REMINGTON ARMS CO. ILION, N.Y. marking, indicating a post-1888, post-bankruptcy factory barrel. This may be a variant of the Remington Model 1891 or 1901 Rolling Block Target Pistols, which were typically built on over run US M1871 Army Rolling Block Pistol Frames. This is clearly a Navy frame and has the remnant of the P/F.C.W. (Frank C Warner) inspection on the right of the and has no factory markings on the left of the frame. The gun was refinished at the time of alteration. It appears that a very talented gunsmith probably added an original M1891 or M1901 Remington barrel to the M1867 frame and then sleeved it to .22, suggesting the original barrel was .25 or .32. A very attractive Rolling Block pistol variant. As a remanufactured antique frame now chambered for a readily available modern cartridge, ATF classifies this gun as a modern handgun subject to all federal, state and local laws and much be transferred by an FFL holder, rather than as an antique firearm. {MODERN}