Redoing the crown yourself.

[Mikem]

Have any of you guys ever redone or polished there own muzzle crown? I read about it being done with a brass round head screw and fine grinding compound in a slow drill, ever heard of this?
My 6BR is not bad, and shoots fine, but could be cleaned up a little.
Mike.

 

[SS427]

I've read on other forums of it being done with a stainless ball bearing and fine grinding compound. I would be concerned about how perfect a brass round head screw would be, so I like the idea of a ball bearing better. I've heard of people using glass marbles too.

Varmint Al has a section on "kissing the crown" with a 1/2 inch Dremel stone, done by hand rather than in a Dremel or a power tool.

I have not used either of these techniques, so can't vouch for how well either method would actually work.

 

[Fred Bohl]

You could lap/polish the crown using the Hart tools/kit shown in the attachment but a good job requires some skill.

I prefer to use the PT&G Piloted Crown Form Tools either 90 or 11 degree to reform a new crown. For just cleaning up dings in the edge of lands (usually from jag/brush back stroke) I use the PT&G Piloted Centering Reamer and just a light cut will do fine - can be done by hand and use a little cutting oil.

 

[markr]

I would be concerned about how the crown got buggered up to begin with. If it shoots fine, leave it alone. not knowing what you're doing, you would probably make it worse, and stay away from it with the Dremel.

 

[tenring]

Brownells sells a crown clean up tool also. I have it on my list for next order. They will usually tell you how to use any tool.

 

[1000yardstare]

Had the brass bolt/grinding compound recrowning method first described to me 45 years ago by an old country gunsmith named Elwood Epps. He maintained the bolt would cause the least amount of damage in the hands of an amateur both to the barrel and to themselves. Care must be taken not to grind an off-center or oval pattern because there is no pilot going up into the bore.

The more aggressive burr type of hand tools tend to chatter if not used properly. The best method is on a lathe but few shooters have access to a lathe or even know how to set one up.

I know two collectors of vintage military rifles who use the brass bolt method to recrown. They say it usually shrinks group size in half. They get their brass bolts out of door hinges.

Expect negative comments from forum members to this recrowning method. Some think it is not "professional" enough.

 

[markr]

Had the brass bolt/grinding compound recrowning method first described to me 45 years ago by an old country gunsmith named Elwood Epps. He maintained the bolt would cause the least amount of damage in the hands of an amateur both to the barrel and to themselves. Care must be taken not to grind an off-center or oval pattern because there is no pilot going up into the bore.

The more aggressive burr type of hand tools tend to chatter if not used properly. The best method is on a lathe but few shooters have access to a lathe or even know how to set one up.

I know two collectors of vintage military rifles who use the brass bolt method to recrown. They say it usually shrinks group size in half. They get their brass bolts out of door hinges.

Expect negative comments from forum members to this recrowning method. Some think it is not "professional" enough.

Just as "most people" don't have any business installing nitrous on their car, so it goes on recrowning a barrel! However, it's yours, do as you wish! ;D

 

[jo191145]

I've done a handful of factory tubes in my basement with various methods. Its not really all that hard to improve a faulty crown. Use your head, think it out and make sure you don't make it worse than it already is.

I've been noticing a lot of factory crowns lately that seemed to have been hit with a polishing wheel causing an off center radiused crown. These are a pain to fix as quite a bit of steel needs to be removed to get them flat. Also must make sure not to simply follow that off center crown.

If its a simple clean up stay away from the drill. Try it by hand first.

If all else fails you'll end up taking it to a smith anyway. I've never ruined a crown yet. Usually I can always see an improvement in accuracy.

 

[Mikem]

The barrel in question is a Pac-Nor Super Match in 6BR, with an 11 deg crown, that has about 800 round through it, but can still shoots well under .250 @ 100, But just needs cleaning up, there's some streaking in a radius out from the bore, that wont come off with just a good wipe.
I feel I'm competent enough to do a clean up job, and could turn a new crown, if I had a lath, I have run them before.
But remembered the brass screw method from years ago, and as the brass is so much softer than the barrel, I dont think I would hurt it, by doing it by hand.
And thanks to all for the posts. Several good ideas.
Evan a green 3-M scrub pad in a circular motion might do the job, it may all be on the surface. Ill look it over good with an eye loupe first.
Thanks, Mike.

 

[Mikem]

I solved the problem my self, first I looked the crown over with a jewelers eye loup to get a real close look at it, then I used a green 3-M scrub pad in a circular motion, and that removed all streaks etc. And I finished it off with brass polish several times, also in a circular motion, and it looks like a mirror. And up close you can see the ends of the lands, that are slightly (maybe .020) recessed below the center of the crown, so it looks like new.
On some factory barrels I have looked at, the lands come right to the outer edge of the muzzle, and could easily be damaged.
Thanks for the help.
Mike.

 

[rain164845]

How does it shoot now?

Joe

 

[Mikem]

Joe, I haven't had a chance to shoot it yet, but I suspect it will shoot the same, (from the mid .1s to the low .3s) depending on my day. As there was no damage, copper nothing, just some streaking radiating from the muzzle. This design would be hard to damage the ends of the lands, but of course the bore is still right at the center of the 11deg crown.
I have muzzle caps for some of my other rifles, but not this one.

Our whether has not been bad by some of you guys standards,
(California) but its been cloudy and cool, highs around +50f when cloudy, and 65+ when sunny. Will hit the range as soon as we get some sun, like it was yesterday.
Mike.