Breech plug question

[L.B. Myers]

Hi All,

My question pertains to breech plug length. I am building an early Lancaster 54 cal. The Green Mt barrel is 1

 

[bob1961]

i think ya can mount it and not worry bout that 1/8"....the barrel will be forward an 1/8" so i don't think it will matter...................bob

 

The advice from Mr Alexander reguards the location of the touch hole on origional guns and builders that are attempting to "duplicate" the architecture of those guns.

On the origional guns the breech plugs were shorter, and the touch holes about 1/8 to the rear of where they would be using modern breechplugs.

This throws off the archecture at the terminus of the back of the pan, back of the breech and union of the wood, creating a little sliver of wood, at the top of the lock, that hangs unsupported back of the upward curve of the pan.

The rear edge of the shield of the pan should actually be in line with the breech of the barrel. Therefore, a properly positioned touch hole should be right at 1/2" from the breech.

This detail is normally unnoticed by the unknowing, but drives educated observers nuts due to the optical illusion thst makes this 1/8" sliver of wood look a half inch long!

Anyone duplicating an origional must

1. shorten the breech of the barrel and the breechplug a corisponding amount.

2. grind a "nick in the corner of the long modern breechplug

3. counterbore the face of the breechplug and create a powder chamber back to the touch hole.

or the duplicate gun will never "look right" when held next to the origional, or even a photo. Shortening the plug is the prefered method, and affects performance and maintainence least.

It is just one of the details that makes the gun a bit closer to perfect.

:thumbsup:

 

[Darkhorse]

If you are building from a kit you are limited in where the lock and breech of the barrel are located. However if planned for in advance even a swamped barrel can be moved back with no gaps and the lock can be moved forward. The reason being to try and get that lock and liner located without notching your breech plug.
While a notched plug can be quick and entirely suitable for a hunting rifle, I find that in situations that require a lot of shooting, such as in a rifle match, the notch can trap fouling and eventually cause hangfires. So I want to avoid notching the plug if possible.
Many of the old rifles had plugs only 3/8 to 1/2 inch in length so it was possible to position the lock fence even with the breech and still have no notch. Unfortunately some barrel makers today breech their barrels deeper than needed. Green Mountain and Colrain both come to mind. With these barrels it will be tough to get the fence back with the breech and not have a deep notch cut into your plug.
Keep in mind, if you cut off your breech plug then you must also cut off that much of the breech end of your barrel. You don't want a bunch of empty threads trapping fouling and corroding.
Most shooters are not concerned with the fence and breech lining up and rifles can function perfectly well without it. Its up to you to decide what you want.

 

[C_Laubach]

L.B.
I would defiantly recommend shorting the breech pin from 5/8" to 1/2". If you fit the breech pin on a GM barrel so that it is timed right correctly putting the makers mark on the bottom, The breech pin usually comes out to be 1/2" long.
:results:

Ghost is right about the length of most original breech pins but as far as the fence of the pan lining up with the end of the breech.....this is up to you. Did they do this on the originals? Yes, some did!....Did all of them do that?....NO!

You also need to take note as to what kind of lock is being used. Most English locks have a longer distance from center of the pan to the end of the fence, therefore making it easier to line up the fence of the pan to the breech of the barrel. Just thumb through RCA 1 and 2 and you will see that lock alignment has been done both ways and you
do not have to line up the fence with breech to achieve proper stock architecture. Take a look at Rifle #42 for example, Thanks to Wallace Gusler I have been able to study this rifle first hand and guess what the fence of the lock does not line up with the back of the breech of the barrel. Now I don't think that anyone in there right mind
would say that this rifle doesn't have proper stock architecture.

Bottom line is it is a matter of preference. If you want to line up the breech with the fence than line them up but don't say that it is wrong to not line them up because that is just simply not true.

 

[L.B. Myers]

Gentlemen,

Thank you for the advice. Although this is a

 

[TANSTAAFL]

I certainly mean no disrespect to Mr. Alexander and many other fine muzzleloader builders. But, it is almost a holy grail fetish with some that the pan fence be at, or in near, perfect alignment with the rear of the barrel.

With that said, not all historically correct period guns were so done. I note that Mr. Alexander also goes into great detail about correct breeching, the nose of the breech plug must form a good seal on the inside shoulder of the bore. He then says he installs a touch hole liner, these come in 1/4" to 3/8" dia. (uh-oh) with a couple in between. Some say it is no big deal if the touchhole (liner) is centered on the face of the breech plug, just drill and tap right into those breech threads for that liner, then grind or file a tapered groove across the breech plug face leading to the touch hole. Right, just make sure you have effected the best seal possible between the breech plug face and shoulder, then turn around and destroy said seal?

If I remember right, there is one problem Mr. Alexander points out, if the touch hole is located too far forward, you may run into difficulty getting the rear lock bolt correctly placed in the lock bolster.

I have no problem with the 5/8" long breech plug being fitted, but, that is just me.

Don't know if you have fitted breech plugs before, but here is a link to how I do it, and offer it as only that.