Any barrel not made specifically for steel shot will wear out over time but there are options. First you could use bismouth shotshells as a steel alternative and it is soft like lead but is a bit on the pricey side. Second, my brother has a model 1200 that he put a 1300 barrel on. It was a direct fit identical barrel but made for steel and with changable choke tubes. Not sure if this will work for all the 1200 depending on age but something for you to look into. His is a later model 1200 not long before they switched to the 1300. Hope this helps.

Or you could just buy another barrel for it that's rated for steel.

Thanks Chester, its actually one made in the 60's and not in the 70's. I might just try to call winchester. But ya know, shotguns are a dime a dozen now days and the 870 remingtons are cheap. Hopefully Cali, doesn't do away with all lead shot. Thanks for the help!