I would do a lot of cleaning on the barrel and chamber with brass brushes wrapped with steel wool or Big 45 strands along with Kroil before I gave up on the barrel. If the chamber is pitted beyond recovery, which I doubt, the minimal taper on the 300 Win Mag will complicate the set back option. I would consider going to 300 Ultra Mag. It will definitely clean the Win Mag chamber and the bolt face is right.
