Mark I think he is asking about opening up the choke, and shot chamber to 2 3/4" chambers if they are not already done. The German shotguns are historicly super full choke, and don't work well with modern shotcup shot shells. My Berrella was opened up by GUN CRAFT in Hurst, Texas, but he has since ritired, and no longer works. Maybe you can give him the Briley Number there in Houston. I don't have any machine tools any longer and can't do the work, but it isn't a difficult mod to do, and only makes the cap gun more useful.