Colt Pocket Navy Revolver Conversion to Cartridge. .38 Rimfire caliber. Frame has the cartridge conversion patent dates. Barrel length 3” (probably was a 4 1/2” barrel originally). Shortened barrel was done during the period of use. Cylinder matching number is faint but visible below the original cylinder number so, all matching numbers. Bore is very good to excellent. Grips are good plus with later on varnish. The shortened barrel was professionally done with a proper muzzle crown job. Overall condition is very good. Really interesting short barrel conversion. Would like to see a photo of the original owner.