This is a single shot Remington 41 rimfire deringer also called a “vest pocket deringer” and was made from 1867-1888. About 10,000 were made. This one retains 75% blue with very good mechanical function and a very good bore. The grips are not chipped, cracked or damaged. This is serial number is 6274 and my best estimate for the manufacture date is the late 1870s.