Is your's a Sears model 21 or Ted Williams Model 21?
Many mfg's made shotguns for Sears. Winchester, High Standard, Itaca and the like. Although I don't have the listing on that particular Ted Williams, My records indicate the the Sears model 21 is a High Standard model K2011, slide action shotgun.
Jim correct me on this:
I am not sure, but if I remember right, although stamped Ted Williams model 21, it will also be the Sears Model 21.
If you are going to use it for hunting and home defense I would go to 20" barrel, and don't forget to crown the barrel after you cut it off. Keep in mind that when you cut the barrel, the barrel becomes a cylinder bore.
[This message has been edited by Harley Nolden (edited June 21, 1999).]