So, lug 1 is engaged, and #2 is very close, but #3 is about .003 away, and I would like to get all 3 engaged, or at least #1 engaged, and the other 2 very, very close (verified by CMM). I have two very old lathes without DROs, a small mill/drill, a surface grinder, pin gauges, and a lug file. Given this equipment, what would you use to cut the .003 off of #2 and #3? I recall seeing something about using a lathe, but this doesn't make sense to me, as you'd also be cutting the underside of the barrel. Then I read something about using a mill, then the file. Seems like a bunch of ways to go. I'm terrified of screwing this up, because there's no fixing this.