FWIW, Stevens made the No.16 Crack Shot using a rolling block action, that had a 20" half-octagon bbl in .32 Short.
Stevens also made the 1900-1916 Favorite Bicycle Rifle No.21 in .32 Long was another rifle issued with a 20" half-octagon bbl.
A 22" bbl (or longer) was standard on most Stevens Rifles, with even longer bbl optional, paid by the inch.
Most of the Stevens Favorite Models used swinging block action's (that can be mistaken for a roller), and the Ideal Model 44-1/2 used a falling block - all those besides the various break-open's, i.e.
With some of the "models", the only difference was the type sights; with others, bbl length/type, etc - so sans pics, a very detailed description might help - but I'm betting in it being a Crack Shot No.16 (1900-1913).
Some of the ID would depend upon if the bbl length is "as issued/original", & not shortened from whatever; AND if the length was measured correctly (a rod downbore from the muzzle to/against the closed breech).
Fun, huh ?
Last edited by PetahW; March 22, 2012 at 06:49 PM.