thanks for the reply's
Thank everyone for the responses. It just blows my mind that they sent it back with a new receiver, that has the exact same problem in the exact same place. I just don't see the point of trying to send it back again for all the hassle it's been to have the same end result. It looks like I will take the suggestion to remove the rust and try a good cold blueing product. Any suggestions? Never took on a project like that. Really didn't plan on having to. Still like the rifle, just seriously bummed about the situation.