Breech plug position question

[Dphariss]

That is the manner of the Indian made Bess'. I do not think it is a good thing, however, hopefully others that know better than I will respond.

I know one thing for sure.That plug in the picture looks like the threads were cut with 2 different
dies or NO dies at all.This junk from 3rd world shops is nothing that we should be shooting and
should not even be offered for sale here in North America.
Bob Roller

Thank you Bob Roller.

Dan

[Dphariss]

Have you removed the breech plug? Unless it's properly done it needs to be rebreeched anyway. And as previously stated  precarves often run into this. If you can make your own vent liner this is an easy fix with the proper counter bore and the right tap. If you cannot do these things you are pretty well stuck.
This is a vent liner being installed with the vent centerline very near the breech face. Picture of the pilot hole counter bored to allow enough threads, the liner being fitted to seal on the shoulder and at the slight counter sink, finished.
This was used with an English design lock with the fence farther back from the center of the pan than Germanic locks like the Siler.
Dan

[bama]

Two things that builders today need to understand about lock placement using our modern breech plugs as compared to many early American breech plugs is our modern BP are longer and have more threads for engagement further into the barrel. Most original BP that I have seen are 1/2” or a little less thread engagement where modern BP have 5/8” to 3/4” thread engagement. This difference will cause your lock placement to place the back of the fence farther away from the back of the barrel if you place your vent at the face of the BP.

The other thing that drives the lock farther towards the muzzle is the use of a vent liner. If you place the vent liner where the inside face of the cone is flush with the face of the BP then you have moved the lock forward half the distance of the ID of the cone of the liner.

These two things alone will cause the lock to be approximately 1/4” farther from the end of the breech end of the barrel if the vent is placed at the face of the breech. Most original rifles did not use a vent liner but had a simple drilled hole for a vent.

There are ways to compensate for these parameters but when you are using a pre-carved stock where the barrel and the lock are inlet then the choices on how to compensate become more challenged.

Most new builders are not aware of all these details and are understandingly confused as to what to do. Layout and an understanding of these parameters before starting a project will eliminate many headaches.

[varsity07840]

I have two flinters with L&R Late English locks where the fence lines up with the back of the barrel, and surprisingly, an Issac Haines with a Siler that I built from a Dunlap kit around thirty years ago. The plug  face is notched. One of the L&Rs is in a patent breech Hawken. The other is in a Leman built from a GRRW kit(not by me) and doesn't have a notched plug, unless it runs across the entire face. I've never had the plug out. None of my other flint fences line up.

[flehto]

When building a very petite Bucks County LR, the 1/4 dia. White Lightning  TH liner is installed so that its upper edge is quite close to the upper corner of the side bbl flat and the top edge of the forestock is below the bbl centerline  and more so below the pan surface. The web thickness at the breech  has nothing to do w/ this post but I make it  1/16" thick which also contributes to being petite. The BC shown displays the above. These BC LRs function quite well w/ this arrangement. The bbl is a ,50 cal.  "B" weight w/ a 1" width at the breech. The  centerline of the actual  TH of the 1/4 dia  White lightning is slightly less than  5/32" ahead of the plug face. Also...there's very little stock protrusion behind the Late Ketland's  fence. The length of the threaded plug on this Rice bbl is their standard  1/2". This post and the pic displays that there can be many variations in building a LR which meets the builder's ideas and  can still be w/in the realm of HC. …..Fred


dnd dice roller

[Waksupi]

I've been guilty of the same screw up. I cut wood to very closely fit the inlet, glued, then re-inlet the lock. Once I got it inlet, I put on a dab of glue and sanded to fill any small gaps left. With dark stain, the repair is pretty much invisible.