WHEN the AW-ban expires next year, I will be installing a flash supressor. My barrel has an 11 degree target crown on it now. Will I have to have the barrel recrowned, or just thread it and go? Thanks for any help.

Even when using a live end on the lathe, you still get some sideways distortion from endplay pressure (even with a spider) that can mar the bore to crown edge.

Best to turn the barrel and make the threads, then pull the live end, and change out to a drill end and re-crown the muzzle with a brass taper (using lapping compound, turned slow). This will give you a chatter free crown to bore edge.

P.S. Remember to center out on the barrel bore, and not the outer barrel surface.