Re: Bolt Face Re-size?
I think it's easiest to just get a new bolt. A 700 bolt will work fine though. If you can, get one without the anti-bind cut in the right lug, though that would be mostly for the sake of appearance.
If you're going to be using the standard 721 trigger group, you'll also need to cut off the piece on the safety that locks the bolt, since a 700 bolt won't have the cutout for it.
Pacific Tool and Gauge's website isn't responding for me right now, but I think they offer replacement 721 bolts. That would probably be the best way to go.