If it will only be 25-50 shells per year, then it's not too painful to buy something like the Hevi-Shot Classic Doubles or some old Bismuth. If it were my gun, I'd measure the chokes accurately and have a smith measure barrel wall thickness, then shoot the occasional steel loads when necessary. Winchester has some steel 1 oz. target loads in #6 that should be a decent load for teal, but I don't think I'd use them on bigger ducks. I bought some at WalMart for my Daly 500 but have not yet had a chance to try them.