Home Forums Hunting & Shooting Hunting Rifles Touching up the barrel crown....brass screw???

I touched up a dinged 30 caliber crown with a bullet and a fine emory paper, it worked OK and gave a better group. If you dinged your crown pretty bad any relief with any tool as long as you don't make it worse will work from my experience.

I can't see anything wrong with trying one of the home "bubba" methods for touching up a crown of poor shooter. Me I would start with a bullet/compound and then maybe the brass screw/compund...if that didn't work I might even try the stone. With a little care, the worse that can happen is you have to have gunsmith recrown in a lathe.

I would try the home method, not because I can't pay the $30 for a smith.. but because to drive 90 minutes.. then drive back 1-3 weeks later for a 10 minutes fix is a PITA

So, if you have a rifle shooting 1" groups at 100 yds, would any of you touch up the crown on it?
Selmer

Consistant 1" groups? Id leave it be..put it in the safe and move on to the next project.

What about non-consistent 1" groups?

Any problems with a crown will be consistent. My rifle cited above was 4" down to sub 1" at 100.

I would love to see an update from 7mmManiac

So yous guys are recommending this for rifle that are shooting patterns, not groups, right? I mean really, if a hunting rifle will honestly put 5 shots into 1 1/2" at 100 yds or 4" at 300 yds consistently, there's no need to mess with it. I've never experienced a rifle with a bad crown, maybe I need to buy more rifles.
Selmer

Interesting how this old thread popped up. I was going to comment as I read along and discovered I had ALREADY posted!!

Selmer, There is no need to guess if the crown needs dressing. I have a rear eye piece from an old rifle scope. When inverted it is one heck of a magnifier. If you do not have such a piece get a jeweler's loop or a strong magnifying glass. Inspect the crown in bright light and look for a tiny imperfection, nick or an area that is shaped differently. If it isn't uniform around the entire circumference it needs attention.

When a known rifle goes sour I always look at the crown. Many times it is the cause of the larger groups.

The gunsmith that showed me how to do this used a lead sphere of about .5" diameter with a brass screw run through it. He called it "ball cutting". The procedure was to chuck the ball's screw in a drill press, then swing the press table out of the way and bring the muzzle up to the slowly spinning ball (charged with lapping compound). Then move the rifle in a cone shaped pattern while letting the ball do its thing.

I tried it on an uncles Savage M99 that one of my cousins had been cleaning from the muzzle and egged out the crown. Recutting brought groups from 4" to 5" to about 1".

jim

Midway USA has a how-to video clip of executing the ol' brass screw procedure on YouTube. It turns up pretty quickly when you search with the likely key words.

Crown video

All I can say is that touching up a crown isn't brain surgery, especially if you use a soft enough cutting tool such as brass or lead. With these you are just taking the little nicks off a crown, not recutting it.

I have recrowned dozens of barrels with a Brownells hand tool, and generally in the end use a leather washer (homemade) faced with a piece of fine emery cloth, both on the face of the Brownells tool. This does the same thing as the various brass/lead techniques described here. It doesn't affect the angle of the crown at all. Instead it just does the final polishing.

Well, this is the first I've ever heard of doing something like this. So, I just used the "bullet in the drill backwards" technique, using the appropriate caliber, boat-tail bullet for each of my rifles. I have a variable speed drill, and went nice and slow. I did the 7Mag, 25-06, the .308, and the .22-250. I didn't use, or have for that matter, any lapping compound. Just the backwards bullet. We'll see if that helped at all.

After using this technique on my 4 rifles, as stated above, I went out and shot them all today. The 25-06 was shooting <1" 3-shot groups with every load I fed it (including some necked down, non-neck turned, 30-06 brass loads that were shooting patterns, not groups before this) The 100gr TSX load was shooting 3-shot groups of 0.8"
The 7mmRM has a featherweight barrel on it, and the 140gr TTSX load shot the first 2 shots into 0.4", and the 3rd with a hot barrel opened the group up to 1.2". Oh yeah, I also pulled that 3rd shot a little

The .308 and .22-250 showed improvements as well, but the improvements were minor, maybe 0.1-0.2" tighter with a 3-shot group.

All groups were fired at 100 yards.

Good to hear you got that Tikka squared away. I did not want to demoralize you with my .270 groups, they went from 1.5" to 1" at 200 with the runout cleared up.

That's awesome shooting!

Thanks for the support and all the advise that helped me get the Tikka sorted out! I'm going to shoot it some more this evening, I'll let you know how it turns out

Here's a picture or two of a target I shot this evening with the Tikka. I used Federal fusion factory ammo. The first 2 shots went into literally the same hole, and the 3rd was about 0.75" from the center of the first hole. The second pic is of the same gun shooting my 100gr Sierra PH load. It measures 0.7"
The 3rd pic is of my Win 88 .308 that I couldn't get to shoot into better than 2" at 100 yards. Today I free floated the barrel after touching up the crown yesterday. This is the target showing the results after two sighter shots, and then a 5 shot group.

Oh BTW, before I get flamed for it, I'm a broke student who's getting married in a couple days, so I have to re-tape and re-use my targets as much as possible.

Or you can go hi tech like this, chunk of red duct tape on a target backer

Very nice video, concise and to the point.