I have a Browning B2000 with a 30 inch long, 3 inch magnum barrel. The barrel is marked Full. I would like to start using the gun for waterfoul this winter on the eastern shore of Md. I have heard in the past that a full choke in a gun designed for lead shot will be too tight to pattern properly when used with steel or other non-lead shot. Is this true? If so, what about having the choke opened up to Mod. or I/M for hunting on the eastern shore with steel shot. What about installing thin wall choke tubes instead? Thanks in advance for any assistance.