These were serial numbered in individual range and this is a Type 6. It is serial number 6615 with 1859 Patent Date on the cylinder. It retains 50% thinning barrel blue. The mechanical function is good plus and it has a very good bore with strong rifling. This is the rounded brass frame and two-piece hammer, which was unique to only the S&W First Issue 22. The grips are nice fitting old bone.