Joe,I don't believe you will hurt the bore with steel shot. The modern wads are that good,but you will hammer the choke out of it. I would have the barrel threaded for screw in chokes if you must use it with steel shot. I had an early 1100 magnum done by Carlsons. Since choking takes place outside the barrel in the extended choke tubes,any damage to the choke won't affect the barrel. Just replace the choke. I got a Carlson stainless sporting clays choke in Modified and it shoots very tight with steel. I agree with you about using your gun. It is obsolete in it's present configuration for ducking. If they end up banning lead for all hunting then there is going to be millions of guns that will be obsolete for hunting unless they are really open choked.