Author Topic: Touchhole Location  (Read 4549 times)

Okefinokee Outlaw

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Touchhole Location
« on: August 22, 2013, 05:25:22 AM »
Please be kind to a newbie.  I'm building my first kit, a Chambers Early Virginia.  It seems to be a wonderful kit, and I don't think I'll have too much trouble with it.  After removing just enough wood at the breech to square up the rounded preinlet corners, I can see that when the lock is installed, the touch hole, when centered in the pan, will be 1/8" in front of the breech plug rather than the recommended 1/16".  Will this be an ignition issue?  Should I fashion a very thin shim to go behind the barrel and sand flush with the stock?  Actually, don't be too nice, tell me bluntly if I'm missing something.   Thanks.

Offline Rich

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Re: Touchhole Location
« Reply #1 on: August 22, 2013, 05:39:42 AM »
I'm not sure why you have the idea that the touch hole should be 1/16 inch in front of the breach plug face. That's ok if you're not using a vent liner. The smallest vent liner Chambers sells is the 1/4 inch white lightning. I install them so that the vent liner is 100% in front of the breach plug (so as to not interfere with the threads and not require notching out the face of the plug). That means that the center of the vent is 1/8 inch in front of the face of the plug. It sounds like that is what you have. If you're using a larger liner, you might want to consider using the 1/4 inch one since it sounds like it will be perfectly placed. Hope this helps.

Offline Long Ears

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Re: Touchhole Location
« Reply #2 on: August 22, 2013, 05:42:16 AM »
Outlaw, everyone has to start somewhere. I assume you are using a White Lightning liner by Chambers. When you say the hole is 1/8" in front of the breech plug do you mean the edge of the liner or center of hole? You don't want to drill into your breech plug if you can avoid it. I like the liner edge an 1/8" in front of the breech and have not had any ignition problems nor excess breech fowling and I have built several and shoot a lot. Everyone else will chine in tomorrow its late on the East side and all those guys are old! ;D Bob

Okefinokee Outlaw

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Re: Touchhole Location
« Reply #3 on: August 22, 2013, 05:58:09 AM »
The center of the hole, when centered in the pan, is 1/8" in front of the breech plug.  I could bring the lock back a bit, but the preinletting for the lock would leave a gap.  The kit instructions advised that it should be 1/16".  But I'm glad to hear that this will not be an issue.  I can see that this is not an exact science, which unfortunately is the way my brain is tuned.  I purchased a Ron Ehlert DVD, and he recommends hitting the breech plug and then grinding a bevel to the center.

Offline D. Taylor Sapergia

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Re: Touchhole Location
« Reply #4 on: August 22, 2013, 06:07:12 AM »


This is a picture of the liner installed in my Chambers' Virginia barrel.  It is a .50 cal barrel, so there is a lot of steel for the liner.  you can see the inside edge of the liner just entering the gap which is filled by the breech plug.  In the .50 cal barrel, the liner is short of the bore by around 1/8", and the hole is such that the liner misses the breech plug face...about 1/8".

Hope this makes sense.
D. Taylor Sapergia
www.sapergia.blogspot.com

Art is not an object.  It is the excitement inspired by the object.

Offline Acer Saccharum

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Re: Touchhole Location
« Reply #5 on: August 22, 2013, 03:39:01 PM »
1/8" in front of the plug is just fine. Taylor's photo says it all.

« Last Edit: August 22, 2013, 03:42:58 PM by Acer Saccharum »
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Okefinokee Outlaw

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Re: Touchhole Location
« Reply #6 on: August 22, 2013, 11:06:48 PM »
Great info.  Thanks all.

Offline A.Merrill

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Re: Touchhole Location
« Reply #7 on: August 24, 2013, 04:53:55 AM »
    When building a gun from a kit that has the lock mortise already cut out you should finish inleting the lock first. Then you can adjust barrel to line up the touch hole with the pan. Good luck.     Al
Alan K. Merrill

4ster

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Re: Touchhole Location
« Reply #8 on: August 24, 2013, 08:03:51 AM »
    When building a gun from a kit that has the lock mortise already cut out you should finish inleting the lock first. Then you can adjust barrel to line up the touch hole with the pan. Good luck.     Al

Ask me how I know that this is advice that should be emblazoned above the workbench.

Offline Paddlefoot

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Re: Touchhole Location
« Reply #9 on: August 24, 2013, 09:42:19 AM »
Just getting started on my first guns from a blank. With pre carves and kits I have always marked out the "desirable" area for the touch hole and adjusted both the inletting and liner position to put the hole in the best possible place. Is it still considered to be best practice to worry more about height off the bottom of the pan than centering it fore and aft?
The nation that makes great distinction between it's warriors and it's scholars will have it's thinking done by cowards and it's fighting done by fools. King Leonidas of Sparta

Offline rich pierce

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Re: Touchhole Location
« Reply #10 on: August 24, 2013, 01:37:29 PM »
I am not sure that small differences fore and aft affect ignition.  But the human eye and mind likes symmetry. And not being centered fore and aft is easy to spot.  I try to keep my touch hole out of the mud. Its humid here in Missouri so keeping the hole above the very bottom of the pan seems wise.
Andover, Vermont

Offline Acer Saccharum

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Re: Touchhole Location
« Reply #11 on: August 24, 2013, 03:32:53 PM »
The bottom of the pan is not the best location. fore and aft a little, and even a little high is all OK.

I try to have the edge of the frizzen cover the TH when Frizz is shut.

There is a lot of mumbo-jumbo about this. Some of the best myth busters to come along are LArry Pletcher's high speed ignition videos.
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Ramrod scrapers are all sold out.

Offline A.Merrill

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Re: Touchhole Location
« Reply #12 on: August 25, 2013, 03:50:35 AM »
    4ster, no I won't ask. I don't want to bring back any pain and suffering. ;D I got lucky I was told just before I went the wrong way. Hope I cought Outlaw in time.    Al
Alan K. Merrill