Quote Originally Posted by browningautorifleicon View Post
Dress those back with a fine half round file. Keep working at it gently until everything fits again.
I tried a small half round file after discovering what I'd done. But I think the initial tapping also managed to peen the edge along that area enough to slightly raise the radius. I'll continue while filing and try threading a spare steel cap into it and hopefully re-cut the damaged threads.

Thanks Jim, I'll check back with any results