They said that they would completely switch out the bolts. I think that grinding the bottom lip off of the rifle might not work, as that would leave a gap below the head and rim. Maybe that would be a problem, maybe not. At any rate, it's not really worth the loss of my principal deer rifle for several weeks, and the $100+.
The rifle already went to Ruger back when I first got it, as the extractor was poorly tensioned. If it isn't broke, I'd rather not "fix" it.