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Hand lapping a barrel?
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Picture of Rich Jake
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Anyone know the proper procedure for hand lapping a barrel? If so would you please explain it to me? I would also be interested in finding out if anyone sells Either a kit or materials for hand lapping. I seem to be able to find quite a few places to buy firelapping kits but, that's not what I'm interested in doing. Any info would be appreciated.
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
<sure-shot>
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My question is why? Is this a factory barrel or custom barrel you want to handlap? sure-shot
 
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Rich Jake

Pick up a copy of the book " Modern Gunsmithing " by James V. Howe. He goes into barrel lapping in great detail. I have observed barrel lapping proceedures at Shilen's facility and it is similar.

Most hand lapping proceedures tend to take out a little extra near the ends of the barrel, that is why it is common at the barrel making facility where they are still a blank and not recomended for a finished barrel.

 
Posts: 1535 | Location: North Texas | Registered: 11 February 2001Reply With Quote
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Thanks for the book title I'll see if I can find it. I was considering hand lapping a new factory barrel before barrel break in.
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
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Craftsman, gave you a very important point. Hand lapping will create problems at the bore and the chamber. It is done in the blank and then the ends removed, then chambered. You will create problems doing it on a finished barrel.

[This message has been edited by Customstox (edited 04-07-2002).]

 
Posts: 4917 | Location: Wenatchee, WA, USA | Registered: 17 December 2001Reply With Quote
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The reason that I asked is that the company that is making the barrel sometimes isn't the smoothest around. So I was thinking that if once seeing the barrel it was in need of attention that I might try it before I went any futher & do the barrel break in. I haven't decided that I will definitly do it. I had one barrel from this company that the tooling marks were pretty obvious & needed to be done. I ended up just selling the barrel & had a custom made which was lapped when manifactured.
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
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While the potential exists to "bell" the muzzle end you would really have to work at it. Once you have done any amount of barrel lapping you will see what I mean. Working with a 400 grit compound it takes a long time and a lot of effort to remove a couple of ten thousanths. For those that may care I'll explain how I do it when lapping a finished barrel (already chambered and crowned)
First I take one of the old cleaning brush cores I save for this purpose and cut the twisted wire core off leaving about 3/4 inch of it. This is sufficient to hold the lap. I then wrap a thin strip of cloth around the base of this. I push the rod in from the chamber end and markthe rod where the wrapping of cloth enters the throat. This way I won't pull the lap out while lapping.
I push the core up to the muzzle end then pullit back about 1 1/4inches or so. Holding the barrel upright in the vise I heat it to about 250 F. I then heat a dipper or pure lead and pour the lap even with the muzzle. After everything has cooled I push the lap out about 1/2 inch then bevel the end. I file a little notch for orientation then push the lap out and remove the cloth strip and bevel that end. I charge the lap with compound then start it back into the barrel. I set the barrel up so that the muzzle end touches the wall and got to work. If there is an obvious tight spot I will concentrate on that. As the lap becomes loose I just ull it back to the breech end then put a rod down from the muzzle and give the lap a good thump to upset it and swell it a bit.
When finished I recrown the barrel removing about 1/8 inch. While many will howl about the lapping of an already chambered barrel I have never had a case where it didn't improve the barrel. Keep in mind that these are always barrels with an obvious flaw like a tight or extremely rough spot. Regards, Bill.
 
Posts: 3534 | Location: Elko, B.C. Canada | Registered: 19 June 2000Reply With Quote
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Thanks Bill
That at least gives me some tools to work with. It also explains why people don't usually do it to a finished barrel.I can understand the reason for the shortening the barrel & recrown.
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
<1GEEJAY>
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Brownell's carry's all the supplies for lapping rings and barrels.
1geejay
http://www.shooting-hunting.com
 
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Thanks I'll check it out.
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
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Jake actually you want to smooth out tooling marks for less fouling. A polish with a tight cloth scag can accomplish this- actual lapping isn't required.

All barrels aren't the same. You might shoot this one first per the manufacturers instructions for break in before any polishing.

 
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001Reply With Quote
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Aladin
Your terminology might be better than mine.I know a few people who have firelapped there new barrels with excellent results,but have heard that this causes damage to the throat which is something that I was looking to avoid. That's why I was asking about hand lapping,but as you mentioned a polishing might be a better way to say what I wanted to accomplish.
Rich Jake

[This message has been edited by Rich Jake (edited 04-11-2002).]

 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
<eldeguello>
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Rich Jake, I would definitely shoot this gun some first, to determine if the lapping is really necessary!! It may shoot fine as it comes from the manufacturer.
 
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Originally posted by eldeguello:
Rich Jake, I would definitely shoot this gun some first, to determine if the lapping is really necessary!! It may shoot fine as it comes from the manufacturer.


I'm definitely going to check it out first visually & then do the barrel breakin,if needed i would then worry about lapping if necessary
Rich Jake
 
Posts: 1213 | Location: Middletown NY USA | Registered: 11 March 2002Reply With Quote
<Pfeifer>
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"Advanced Gunsmithing" by Vickery is also known for its coverage on barrels. Just rounded up a copy recently. Jeff P
 
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