As Oldtimr said, same is true for your Auto5. Get your self some Nice Shot or some Bismuth shot, both are safe for the older Brownings. With that said, many folks still shoot the smaller size steel shot (4 to 6) in the more opened chokes like mod and imp cyl. I shoot Bismuth out of my Belgium Browning light 12 but it costs me an arm and a leg so I tend to save that gun for the dove field. Get yourself one of the Miroku made barrels for your older Auto 5 and you can shoot all the steel you want. What choke does your Auto 5 have?