Two Hands, I'd have to disagree with BadgerArms a little here. I lap lugs until they have at least 90% contact and headspace is always a consideration. If you have one that is on or near the line between go and no-go lapping the lugs could easily lead to difficult extraction and other symptoms of excess headspace. The barrel should be removed and either an old barrel stub with shims or a special lapping tool used to put pressure against the bolt while lapping. If necessary then the headspace is corrected. George