I have found a 2 1/2 12 gauge with 2 sets of barrels. one is cy/cyl, the second set is ic/mod.

Is it feasible and practical to convert the cyl/cyl set to 16 or 20 gauge? The shotgun now weighs 6lbs 3 oz with either set of barrels. Would the conversion/sleeving add much weight? Any thoughts on cost?

If it isn't a bad idea, who would you have do the work?