Look/ask on
www.savagesingleshots.com. The guy that runs that site literally "wrote the book" (you can buy one, too!) on Savage 219/220s.
One of the "myths" about these 220 rimfires is that they were made to kill pigeons and other pest birds in aircraft hangars in WWII. Unverified as far as I know. Does yours have an offset firing pin or an offset bore?
These guns are pretty rare as far as I know, and they were made long before the Mossberg M0-Skeet-O guns, prewar, I think. You can date it roughly by the factory it was made in--if it was Utica, NY, it was probably prewar or right after the war. If in Chicopee Falls, MA, it was postwar.
