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

I read a post a few weeks back about using a brass screw in a drill to smooth up the crown. How do you pick the screw size and what shape head? What cutting/lubricating fluid should you use? Any help would be appreciated.

If you just want to smooth it up a little, use a spitzer bullet that is a caliber larger and chuck it in a drill. Coat the contact area of the bullet with a very fine valve grinding compound and proceed slowly.

I used a small round dremmel grinding ball in a variable speed drill with a drop or two of light oil on the crown. I wanted to use something round figuring I had the least chance of making it lopsided. I used a low speed and just touched it up - a few seconds at most. The improvement in group size was immediate.

To touch up a crown I use a method like Kenjs.

Link

Thanks for the info. Sounds like the bullet method would be less 'intrusive' for a beginner. Although, I do have a dremel with plenty 'o tips... I think I feel an 'OH Schitt' coming on! Gotta love power tools.

Since your removing a little blueing, should you touch it up or will the gun oil, carbon, etc take care of it?

I would not use the Dremel motor at all. Its way too fast.

Use a battery powered variable speed drill with that Dremel stone in it or another tool or a bullet.

Do it like I wrote in the link. Your only breaking the corner on the crown. Do a little and shoot it. Then do it again deeper if it needs it.

I've done it on a couple of rifles and it worked fine improving groups sizes. I used a slotted brass screw about 1/2 again larger than the bore with extra fine grinding compound. I plugged the bore about 1" back with tissue to keep the stuff from dribbling down the bore. The brass screw was chucked in a drill.

The only tip to remember is to rotate the drill in a circular motion over the bore instead of holding it still kinda like stirring a spoon motion. This will help keep the work centered.

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Brownells sell a cool little kit with different sized brass tools for a power drill..

Here are two crowns I broke the corners on and now they shoot very well. I am pretty sure the one on the left is a .277".

The Dremel tool I showed does not cut smaller bores well as it goes in too deep for a good looking cut. Otherwise it works.

I used the brass screw in a drill with some 600grit compound and touched up the crown on my Kimber, huge difference and now all is good.

You guys all sound confident using hand held drills and dremels turning screw heads and backward bullets into a rifle crown, but it makes me cringe. I cannot see how anyone can place an even crown on a barrel, regardless the degree, w/out using precision equipment.

GVA

It does not seem to matter. The rifles group. Then just sight them in.

Well...I see this as a last ditch effort at trying to turn a avg shooting rifle into a better shooting rifle, not match grade, as someone posted elsewhere, I have no misconceptions about possible improvements. If it doesn't work and or does damage...SO WHAT! It's a turd anyway and will hold up a tomato plant come next spring! Thanks for the input guys.

All you are doing is removing a very small amount off the edge of the rifling at the end of the bbl, giving it a new crown.

I was scepical, but have ahd good results a couple of times doing it.

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The cool thing about using a sphere shaped cutter/stone is that you cannot cut the crown crooked.

I use a carbide cutter called a burr. Most of the time I use it in a brace. A few turns with light pressure and oil will do it. A small pc of oil coated 600 Wet and dry sandpaper shaped to conform to the sphere polishes up the finish. It has brought accuracy in many rifles.

There are actual mandrels out there for this, and are not expensive at all.

I bought all 3 sizes from Brownells, and have helped many a factory rifle shoot to its ability.

I even got a carbon buildup in a Hart barrel, that took many passes with JB to get it out.

I washed out the crown in the process but was able to bring it back with the mandrel, and it shot better than before.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=718110&t=11082005

Azshooter - that seconds what I was saying. Round at any angle seemed like insurance for, well, staying round. No knock on the other methods as I'm sure they work. I was sceptical but mine was already jacked up anyway by someone I paid to do it! It was a mess soooo PLAN A - find a REAL smith, Plan B -If I tried and botched it - refer to Plan A. I was all smiles when I saw that hack job turn into a nice perfect ring on the crown. I remember thinking after just a few quick touches "Hey that 'looooks' better right????? Thought so - so what the heck. So I stopped. I have to admit that I was dang pretty bow-chested next time at the range. It shot so much better. I was grinning thinking.."yeah, I did that!" Stupid little thing like that really gave me a boost.

If it were me,I'd never mess with my rifle crown,I'd have my gunsmith do it.If you mess it up,barrel won't shoot worth a crap,if you go to far might have to cut off barrel.

Critter, you should not be going that deep at all using any of the above methods. When I did mine the crown just looked bad, no major angle problems, just a bunch of chatter marks. I could not measure the amount of material removed but it was pretty small.

As far as I know, there's isn't a 'good' gunsmith within many many hours of my house. If there are, I haven't heard about them. (So no offense if your good and live close, if so..pm me.)There are plenty of jack leg wanna be's around, so I'm pretty leary. One guy was claiming all sort of stuff, 20 yrs here, 10 yrs there, yada yada...I went to his shop and looked at a few of his 'customs'. Well...I'll just that a retarded monkey with a screwdriver and a ballpeen couldn't have done any worse, hell...I couldn't have done any worse. Surplus mauser actions with A&B barrels in the ugliest stocks on the planet. Imagine a Savage crossed with a Mosin Nagant...pretty close. And they were a steal at $700.00 ea.