[woodstock]

It can be recrowned. Not a big deal. You can also sometimes find brand new take off barrels pretty cheap on ebay if you want to just replace it.

 

[woodstock]

Or you could spend a few bucks for the right tool. POWER CUSTOM BRASS MUZZLE CROWNING LAP | Brownells
Although Grumpy has a pretty good idea if you have those kind of problems. Wife problems I mean.

 

[woodstock]

Glad I could help and welcome to the forum. Let us know how it works out.

 

[woodstock]

Not sure what your asking. Maybe it would help if you could post a picture of the damage. The top lap in the link I posted about should be the one you want.

 

[woodstock]

My assumption is the lapping tool is inserted into the barrel at the muzzle to lap it round. Am I incorrect?

Yes, but on the ones pictured only the round tip is placed against the muzzle with some lapping compound, the straight shank on the other end is to chuck in a drill to spin it. It doesn't actually go down inside the bore, just right at the outside edge of it.

 

[woodstock]

The ad for the lapping tool suggests 600. I wouldn't think you would want to run it too fast either.