I know a couple of people who continued to use their Remington 870's and Browning Superposed after steel shot became the norm for waterfowl. Worth Mathewson also writes about using steel, lots of steel, in a Browning O/U and in an LC Smith SxS with F and F chokes. None of these people report barrel damage. One 870 has been patterned with every size from #4 to T, and patterns best with T and #3 steel! I did not see the patterns, but I bet they were, well, not the best Full choke pattern I've seen...They kill birds, that I have witnessed. I've read on this site that a person experimenting with chokes found much improved patterns and percentages at about .018" for a 84% pattern! IMO, there is no reason to keep a full choke in a barrel used for steel shot.
