Breech plug HELP

[Mike Yancey]

I have made a huge mistake in inletting a lock, the gun is 99% done and when I put the liner in today I realized that the hole was 3/8 forward of the breech plug.

I am looking for someone that can build up the breech plug or make me one that will work. The powder wont come up to the hole.

Mike 479-474-3800

[Daryl]

Must be a small powder charge. I'm not used to those.

[Ky-Flinter]

Mike,

What diameter is your touch-hole liner?  With a 3/8" liner I put the hole about a 1/4" ahead of the breech plug face so their threads don't interfere with each other.  I don't think you're that far off. 

Ron

[Scota4570]

Better that than notching the plug, IMHO. 

Is the touch hole not somewhere in the pan?

We need pictures.

[smylee grouch]

Yep, unless you want to notch the breech plug the hole should be about half the diameter of the liner in front of the plug.

[Pukka Bundook]

As long as touchhole and pan line up, it should be good.

[JTR]

The powder wont come up to the hole.

I think attention needs to be paid to the last sentence.

If the powder won't come up to the vent hole, that means the patch on the ball will, and will cover, or partially cover the hole.

The simple solution is to add more powder, but, given the caliber that might not be a good idea accuracy wise.

[Daryl]

At 3/8" ahead of the plug's face, how light a powder charge are you planning? What calibre?
The middle of the vent would then be .5625" ahead of the breech plug face, if the vent is a
3/8" vent.(middle is .1875" from ea' side. It will be under .5625" if using a smaller vent.
I think it will be fine, but if you dry ball, that is put a ball down without powder, you will likely have
to pull it, won't be able to shoot it out by putting powder into the chamber (rear of the barrel) though
the vent.

[Mike Yancey]

Guys its a 20 gauge fowler and I inlet the lock too far in front of the breech plug. 100 grains of 2 f wont come to the touch hole. I have a machinist that is building up the end of the breech plug and going further past the threads towards the touch hole.

The lock and pan are in the right spot as far as the touch hole goes! Its just that I set the position of the inlet too far forward when I  marked the inlet for the lock.

Its being fixed.

[Cody Tetachuk]

. I have a machinist that is building up the end of the breech plug and going further past the threads towards the touch hole.

Its being fixed.

Unless I misunderstand your "solution", this plan is trading one problem for another. If you are having the breech plug extend as a blank plug (not threaded), you will have to remove the plug every time you clean the gun to get the fouling that WILL get in between the "false plug" and the barrel. That would be an unnecessary PITA. IMO (such as it is) is that to fix your issue properly, the threads in the barrel should be tapped deeper to the proper length (just short of the touch hole liner) and a new breech plug made to the proper length for the new longer barrel threads. A properly fitted breech plug has to butt up tight to the shoulder at the end of the threads in the barrel to seal out any fouling. A blank (unthreaded) extension will not be tight enough to provide this seal.

[Daryl]

That suggestion makes total sense. New longer threaded plugs.

[bob in the woods]

That suggestion makes total sense. New longer threaded plugs.

Exactly. The barrel needs to be drilled and tapped deeper, with a longer breach plug.
The plug needs to mate up with the shoulder of the threaded barrel to make a proper seal. That's what fitting the plug is all about. 

[RebelSon]

I know it's not what anyone's first choice..and I'm still not understanding the problem as described..but, why not "plug" the current liner location and blend everything and re-drill at the desired location for the liner?

[Daryl]

Because the lock is in the wrong place, already inlet?

[RebelSon]

You're right, Daryl! I went back and re-read the whole thread..this is what I get!

[smylee grouch]

It appears there is some confusion in the translation of the OPs statement " building up the end of the breech plug ". I'm hoping that the plug will have threads its full length otherwise it will create an un-cleanable fouling trap.  As Scott said pictures would have helped.

[bluenoser]

Trying to visualize how one would extend a breech plug and then extend the threads.  Not having much luck.  I know how to pick up a thread on a lathe and I guess one could run the lathe in reverse, but mounting the breech plug would seem to be a PITA.  I would think it simpler to make a new plug and then transfer the tang.

[Daryl]

Bingo, easiest fix I can see.

[RAT]

I don't think you can "build up" the end of the existing breech plug and either make it work, or make it safe. What you could have a machinist do is machine an entirely new breech plug with a thread longer than you need. Then you would fit the new breech plug like normal to ensure a proper seal between the face of the new plug and the shoulder inside the barrel. Having him machine the tang portion a bit oversize would allow you to re-inlet the tang without having to worry about gaps with the wood.

[Dphariss]

I have made a huge mistake in inletting a lock, the gun is 99% done and when I put the liner in today I realized that the hole was 3/8 forward of the breech plug.

I am looking for someone that can build up the breech plug or make me one that will work. The powder wont come up to the hole.

Mike 479-474-3800

You gotta draw this all out and pull the breechplug so you KNOW whats going on. Other than boring the barrel deeper and fitting a breech with REALLY long threads I don’t see an easy fix.