over lapping a barrel

J

Jhart

Guest
I sent a 6groove barrel back to the manufacturer the other day for exsessive copper fouling,
they told me it was because it was over lapped :confused:... So i guess there going to lap it with 100 grit compound and send it back.. sound fishy to me!

Has anyone ever herd of this over lapping "TECHNIQUE" before ?
 
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I suppose they figured it was too slick. I have heard that too slick of a finish will cause copper fouling, but I have never experienced it.

That being said, lapping a barrel after it has been cut to length and finished is not a good idea. I would demand a new blank........jackie
 
Jackie,
I will disagree somewhat. I sent one back to one of the barrelmakers that you use with a copper fouling problem. It was a 4 groove. They did a light 320 grit lap and it quit fouling. It shot the same as before hand. An experienced lapper does not lap enough to hurt a barrel.
 
Not only will a too smooth barrel foul easier it will also change the vibration pattern. Tracy Bartlein and I had a long talk about that one time at St Louis.

A barrel will excessively copper if it has a bulge in it. Sometimes a barrel will have an inclusion that the lapper tries to get out is what normally creates this condition in BR quality barrels. For that reason, especially, is why I always slug a new blank before I start to fit it.
 
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Jerry, how do you slug a barrel ? is this something i could do myself and what does one look or feel for while doing this.
 
Try this when you're sanding paint off a stock or anything for that matter.

start an area with 60 grit, then quickly change to 80, 120, 220, 320 etc....

there is a point where you'll notice the paint comes off quicker, it's not the 60 either, it's the point where there is more grit contacting the paint at the same time. I've thought about this with barrels too... Guage blocks when they are super smooth... they stick together as you rub them back and forth... surface contact.

If your barrel was that smooth and your bullets that smooth wouldn't they want to stick together, heat up faster, build more pressure, foul faster?

What if the barrel were coarse enough that the bullet rode the ridges so to speak and the valleys were not so deep that they would gather too much copper? You are looking for a perfect happy medium right?

Paul
 
Guys,
I have a question. Are you guys lapping brand new barrels directly from the manufacturer?
 
Jim,

The best articles out there about slugging a barrel, were done by Bill Calfee. You can search this sight, or rimfire accuracy.com sight and probably find the info. If not, let me know and I'll try and remember to make you a copy of the article(s) and send them to you.

Hovis
 
AJ in Kansas said:
Guys,
I have a question. Are you guys lapping brand new barrels directly from the manufacturer?
Click to expand...


No it came this way.. All i know is the turd won't shoot more then 3 rounds without galling the jackets off the dam bullets. And they think relapping a chambered barrel is a better idea then replacing it.. WHATEVER!!!!!
 
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