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DiN BLiX
August 12, 2004, 11:11 PM
I have a yugoslav sks that i have chopped of at 18 1/2 inches on the barrel. I refaced the muzzle on a mill and used a counter sink to crown it. my question is, does the crown have to be perfectly sqaure with the muzzle or can it be alittle lopsided? I know that burrs on the crown can destroy accuracy but i cant find any info on this.

mete
August 13, 2004, 05:14 PM
If the muzzle is not square with the bore as the bullet just leaves the muzzle there will be more push from the gases on one side of the bullet than the other. This makes it inaccurate. Square and no burr is the way to accuracy.

DiN BLiX
August 14, 2004, 04:21 PM
Are there any low tech ways of fixing a off center crown? i cant afford to take it to a smithy.

Casp_A
August 14, 2004, 07:45 PM
I'm certainly not an expert, but what I've been taught is that it doesn't matter how wide the crown is or what angle the bevel is at, just make sure that it's completely concentric. I would imagine that, if there's plenty of metal left, just redo it with a slightly larger countersink and take more care to keep it on center. But then I also recommend getting the opinion of someone who knows slightly more about what they’re talking about than me.

DiN BLiX
August 14, 2004, 11:53 PM
Yeah im haveing problems finding countersinks with a .30 cal pilot shank, any suggestions?

mtnboomer
August 15, 2004, 02:42 AM
Brownell's has a tool to cut and square a crown. It uses a pilot in the bore to keep it square to the muzzle.

http://www.brownells.com

DiN BLiX
August 15, 2004, 09:36 PM
Wow cant afford one of those.

dfaugh
August 21, 2004, 07:59 AM
I've never seen a "home grown" muzzle crowning procedure that really worked...I tried a couple my self....Save your money (and frustration) and get the proper tool from brownells...I bought the facing tool (to square the end) and the 11 degree cutter....after that I bought the pilots as I needed them, which are cheap...Use cutting oil (or I just use WD-40) and the cutters will last a long time...I've now done several rifles with them...Sooner or later you'll wanna do others, and the cost won't seem so high.

P.S. Shouldn't you be able to get a dead-square cut on a mill if you set it up right?

dfaugh
August 21, 2004, 08:01 AM
You'll want the .311 pilot (not .30 caliber which is .308).

Harry Bonar
January 25, 2005, 09:59 AM
Dear Shooter:
There are barrels too short to go in my lathe; I know it's not kosher but I use a file and square to get the muzzle as square as the eye can see. Since the barrel is tapered I know this isn't precise.
After I get that muzzle as square as I can see I use a trick an old gunsmith taught me (Dave Taylor of Little Hocking Ohio who has passed) and take a regular sharp countersink and put about two or three thicknesses of denim on the muzzle, keep the hand drill straight as I can and crank - it produces a clean crown! Try it and them sometimes to get rid of the burr I will lap it using a brass bar between the hands with some lapping compound on it. Does a pretty good job. I've seen "crowns" put the bullet 3 feet off!.
Hope it works; but the Brownells tool will do better. :)

Lazy D
January 25, 2005, 08:42 PM
that has the hand crowning reamer setup. I use the Dave Manson setup. It produces a crown equal to or better than a lathe can. It only takes a few minutes, and I charge $30.00 because it is so quick and easy. Now the Manson reamer setup is about $400.00, and it will take some time for it to pay for it's self, but by giving a quality and economical service I get more jobs by word of mouth. Good Luck