Crap reamed chamber is not something that you horn out to enlarge the chamber side wall demensions,

You can run a finish reamer in the chamber to clean up high ridges that where not reamed correctly, but low grooving channels, consider the barrel defected and need to be replace.   The reason for this, when the chamber is horned to increase the side wall dimensions over spec, it just going to lead to a over expanded fire form case, and if you have even see a mag well mushroomed out for the split case at firing, see why trying to save a crap barrel ends up with more parts on the rifle destroyed in the long run instead.