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Old June 16, 2009, 10:55 AM   #1
azredhawk44
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Join Date: September 28, 2005
Location: Mesa, AZ
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Recrowning barrel

I have an ancient "Coast to Coast hardware" model 42 (basically a Marlin .22 semiauto) that is shooting for crap, and I know it's the rifle and not me since I compared relative accuracy to me shooting my M14.

Lots of horizontal play.

I've checked the action screws to make sure it's retained in the stock properly.

The sights are stable, not loose. No play in them at all, front or back.

I've loaned this rifle out quite a bit as an Appleseed loaner when a shooter shows up with a relatively inappropriate rifle for the lessons we teach. Quite a few of the recipients of the rifle have been absent-minded kids that have put the muzzle down onto concrete or into the dirt. Grr. Argh.

The accuracy has gone way downhill since I began loaning it out. Go figure.

Anyways, I was thinking of trying my hand at re-crowning it. I have a pneumatic die grinder and air compressor in my garage, and a grinding stone for it that should give it a nice protected recessed crown.

I've been told I should use valve grinding compound as a paste between the muzzle and the grinder. I can't find any. Is there another suitable material to use?

This rifle is not dear to me and makes for a good project rifle to learn about crowning... I have a new Marlin autoloader that is my "good" .22 so I'm not too worried about ruining this one if the worst comes to pass. I'd still rather do it right, though.
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Old June 16, 2009, 11:33 AM   #2
Joat
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Location: Dayton, TX
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Check at Checker Auto, Pep Boys, or Autozone for the valve grinding compound. It is usually in the "specialty" tool area with the mechanics stethoscopes, feeler gauges, ring compressors, etc. Two little cans (about twice the size of a blistex tub) shrink wrapped bottom to bottom. or permatex puts it in a tube permatex 34A.

Instead of the grinding stone, use a large, round head brass screw. That way the compound is doing the cutting not the stone.

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Old June 16, 2009, 02:47 PM   #3
drail
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It will be difficult to keep the crown perpendicular to the bore with a hand grind tool. You need to use a piloted tool to ensure you are maintaining the 90 degree crown to bore angle. Brownells has these cutters.
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Old June 17, 2009, 02:04 AM   #4
impalacustom
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If think the people meant to tell you to get some valve "lapping" compound as this is a paste and valve grinding compound is a lubricant that is used as a liquid on valve grinding machines.
Not exactly how I would do it but here is how Larry Potterfield does it on You Tube. Just ignore the part about cutting your barrel.
http://www.youtube.com/watch?v=b43odFm0mrI
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