I shoot Briley tubes all the time. There 20's work fine in a 12 and due to the added weight recoil is reduced. The tubes are strong enough that I would not hesitate to shoot them in thin out of proof barrels. I routinely put about 10,000 shells a season through a set of 20,28, and 410 tubes and after 5 seasons have had no problems. They would need your barrels to fit the tubes. bill