Rather than risk ruining it, I would get a different bolt body. I realize you would not do that on a matching number gun. You could try a some very fine valve lapping compound , lather it up, and work it 5 maybe ten cycles tops and call it good. That shouldnt remove the hardened surface. If you have already gone too far you will have to reharden.
Another big mistake is trying to get the locking lugs evened up. That is another easy way to ruin one as it is very difficult to reharden the lug seats. Strip the bolt, lather the lugs with very fine valve lapping compound, slip the bolt in, put a cleaning rod down the bore, put pressure on the cleaning rod against the wall and work the bolt 4-5 times and call it good.
