Author Topic: Lyman/Investarms Breech Plug  (Read 8746 times)

kendog

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Lyman/Investarms Breech Plug
« on: June 05, 2009, 02:14:03 AM »
Hello;
 New guy here.
 Has any one here ever pulled the breech plug from a Lyman Great Plains caplock? The one I have is VERY tight, and I would like to get it out without destroying it. Got hold of the hook with a wrench, but it will twist off before the plug unscrews. My last resort would be to chuck it in the lathe and take a relief cut at the plug/barrel joint. Any help or ideas would be appreciated.
Thanks in advance.
Ken

Offline Dphariss

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Re: Lyman/Investarms Breech Plug
« Reply #1 on: June 05, 2009, 05:01:59 AM »
Hello;
 New guy here.
 Has any one here ever pulled the breech plug from a Lyman Great Plains caplock? The one I have is VERY tight, and I would like to get it out without destroying it. Got hold of the hook with a wrench, but it will twist off before the plug unscrews. My last resort would be to chuck it in the lathe and take a relief cut at the plug/barrel joint. Any help or ideas would be appreciated.
Thanks in advance.
Ken

Its likely machine installed and is very tight as the early (at least) TCs  were or the fit was loose and its been glued in with locktite or similar.
Try heat, 300-400 degrees on the barrel.
These things are put together to sell at a "competitive" price. They can't afford to put them together as they should be.
The other possibility is that its got a fouling trap and the plug is rusted in. If its been used with certain "replica" powders this is good possibility. Most guns of this type have significant fouling traps at the front of the breech threads.

Dan
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Offline Mad Monk

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Re: Lyman/Investarms Breech Plug
« Reply #2 on: June 05, 2009, 07:09:58 PM »
Hello;
 New guy here.
 Has any one here ever pulled the breech plug from a Lyman Great Plains caplock? The one I have is VERY tight, and I would like to get it out without destroying it. Got hold of the hook with a wrench, but it will twist off before the plug unscrews. My last resort would be to chuck it in the lathe and take a relief cut at the plug/barrel joint. Any help or ideas would be appreciated.
Thanks in advance.
Ken

The BIG question is why you would want to pull the breech plug.
It will be most difficult to get it back in properly sealed and lined up.  Investarms uses a sealant on the plug threads that is difficult to remove once you do get the plug out.

E. Ogre

J.D.

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Re: Lyman/Investarms Breech Plug
« Reply #3 on: June 05, 2009, 07:31:53 PM »

The BIG question is why you would want to pull the breech plug.
It will be most difficult to get it back in properly sealed and lined up.  Investarms uses a sealant on the plug threads that is difficult to remove once you do get the plug out.

E. Ogre

I was wondering that too. I had a Lyman GPR about 30 years ago that went squirrely after shooting for a few years. I tried everything under the sun to remove the plug so's I could lap the barrel, in an effort to return it to some semblance of accuracy. The plug would not come out, period. Heat from a acetylene torch wouldn't budge it, even after soaking in penetrating oil for a coupla weeks.

If your barrel needs work, it is easier to replace it than to try to pull the plug for whatever reason.

If you just want to look at the bore, buy a bore scope. Buying the 'scope will save you tons of frustration, anger, and a possible aneurysm, at the very least, and a ruined barrel at the worst.

kendog

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Re: Lyman/Investarms Breech Plug
« Reply #4 on: June 05, 2009, 09:45:51 PM »
Thanks for the quick replies.

 The reason I want to pull the breech plug is to plug a vent hole that SOMEONE (me! :-[) drilled many years ago. It would be much easier to hold it in the mill vise for drilling and tapping without the barrel hanging off of it. I have a replacement plug, and breeching it up and indexing it, or refitting the original, shouldn’t be any more difficult than a modern bolt action or a M1/M14 rifle, but I would like to save the original, if possible.
 The vent was a good fix for hang fires, but SOMEONE (me :-[) put it in the wrong spot and I am tired of getting my support hand coated with black powder fouling. Thought I would plug it and put a smaller one in a different location.
 I am aware that CVA had some type of proprietary breeching, just wondering if Investarms did too.
 Maybe I should just leave it alone and live with the mess. This barrel shoots pretty darn good with 65 grains of 2F and a .530 ball, and has won it's share of trophies at local trail walk shoots for the last 18 years. It's a 48" twist, and is pretty accurate if I keep the charges low.
Ken



The BIG question is why you would want to pull the breech plug.
It will be most difficult to get it back in properly sealed and lined up.  Investarms uses a sealant on the plug threads that is difficult to remove once you do get the plug out.

E. Ogre

I was wondering that too. I had a Lyman GPR about 30 years ago that went squirrely after shooting for a few years. I tried everything under the sun to remove the plug so's I could lap the barrel, in an effort to return it to some semblance of accuracy. The plug would not come out, period. Heat from a acetylene torch wouldn't budge it, even after soaking in penetrating oil for a coupla weeks.

If your barrel needs work, it is easier to replace it than to try to pull the plug for whatever reason.

If you just want to look at the bore, buy a bore scope. Buying the 'scope will save you tons of frustration, anger, and a possible aneurysm, at the very least, and a ruined barrel at the worst.
« Last Edit: June 06, 2009, 11:35:14 PM by kendog »

J Shingler

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Re: Lyman/Investarms Breech Plug
« Reply #5 on: June 06, 2009, 10:10:54 PM »
I have a couple of those from back in my percussion days. Good shooters and have brought home plenty of prizes with them too. The Planes rifle with the brass had a 1:48 twist but the Great Planes Rifle with the iron hardware is or at least was a 1:66 twist. Sorry can not help with the breach plug removal as never had to take mine out. My guess is a little heat and a fitted wrench is going to be needed.
Good luck on your project.
Jeff