Can anyone here tell me if this is serious damge or not? I have a Colt New Frontier 45colt. If I hold the barrel pointed up at the ceiling and look closely in at a shallow angle at the inside of the muzzle I can see the grooves and lands.The top of each of the 6 lands right at where they end is worn off or smudged. One is wider at one side of the land than the other, another looks like it has tiny pits in the smudge.But all the lands show some sort of wear angled off before it fades out to the barrel wall. Grooves all look fine. It only sees LSWC bullets at Colt SAA power and when I clean the barrel I use the brass cone muzzle guard .Brushes are bronze.IS this normal ? I am still not happy with the way it shoots but I have on occasion been able to shoot 5 shots at 15 yards tightly into an inch or 1.5" . Usually I get 3 shots in and 2 shots out.Wouldnt a bad crown give me total erratic patterns?
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A damaged crown never helps anything, that's for sure.

My mental image of what you describe does sound like damage. If you can't do a re-crown yourself, any gunsmith can do it for a few bucks.

I've done a few re-crowns with a half-inch polishing ball intended for a Dremel. But I never run it that fast. I use a low-speed screwdriver, oil the crown and press down lightly with the spinning ball. I slowly rotate the screwdriver in a conical pattern to avoid pressing at one angle. Five seconds is all it takes.

Any asymmetry in the crown will make top accuracy impossible. What happens is that as the bullet base exits the muzzle, pressure starts venting from the low side of the crown first and that tips the bullet. With lead bullets it also can blow a little extra metal off that side, leaving the bullet unbalanced to wobble through space.

I saw a magazine article one time in which a fellow recrowned a revolver by chucking a roundhead bolt in his drill, putting valve lapping compound on the head and into the screwdriver slot and spinning it down against the muzzle. He got a remarkable accuracy improvement. The idea is that the ball will tend to walk to the low side of the crown, which sounds bad, but actually means it will tend to make a larger contact area there that cuts more slowly than the high side. The result is a tendency for the high side to cut faster until it catches up with the low side. Once even, the ball tends to remain centered.

I looked at doing this, but using a draftsman's hole template (this was back before computer drafting was ubiquitous) I determined that the round bolt heads in my hardware store had profiles that were actually elliptical, not round, so tilting them would result in cutting toward the drill. Constantly rotating the barrel may compensate for that, but I didn't try. A drill press or other means of keeping the elliptical bolt coaxial with the bore would be needed.

Instead of the bolt, I super-glued a large ball bearing to the open end of a piece of tubing. I grooved the ball surface in a cross-hatch pattern with a Dremel cut-off wheel to help it hold abrasive compound. I used it by holding the barrel between my knees and spinning the tubing back and forth between my palms, like trying to start a fire with a stick. I rotated the barrel position about a third of a turn every ten spins, so the pressure into the crown would average out to be even. I started with 220 grit and worked my way down to 1200 grit, then used some polish. I wound up with a mirror finish crown so sharp it would cookie cut any patch pushed in from the muzzle until I had shot it for a bit.

I have an image file that shows the ball and how to choose its size to achieve a particular crown angle coming off the edge of the bore. I am away on a business trip at the moment, so I don't have that with me, but will try to remember to put it up when I return. I also should mention that I first cut the old crown off square before doing this, but you would only need to do that if find your lapping isn't making the new crown even.

If you didn't want to make your own tool www.brownells.com (http://www.brownells.com) should have what you need