Re: copper plated leadand barrel?
Shot is plated with copper because it is harder than lead and helps prevent deformation when the shot goes through the choke. It is nowhere as hard as steel shot and it will not hurt your barrel. Copper plate has been around for a long time and used to be a favorite of waterfowl hunters before lead became illegal to use.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!