Manufactured circa 1851-1860, this example is the earliest type with the manually revolved six-shot cylinder. Total production on this type was approximately 900. A Colt lawsuit forced Massachusetts Arms Co. to switch to manually rotated cylinders, and led to the adoption of the Maynard priming system in an attempt to win over potential customers. "18/618" marked on the frame inside the primer area, with "618" also on the underside of the primer door, right of the grip frame and handwritten in black ink on the underside of both grip panels. "248" marked on the underside of the top strap.

Fine, retains 50% plus original blue finish concentrated on the barrel, latch, cylinder and primer door with smooth gray patina on the balance, strong patterns of case colors visible on the hammer and top strap, and sharp engraving. Grips are also fine with scattered scratches, some light crazing along the bottom edges, and retaining most of the original varnish finish. Mechanically excellent.