timeing breech plug to a particular flat when plug length and hole depth are the

[smylee grouch]

where does one remove metal when you are trying to get the trade mark down on the bottom flat and you bottom out on the top flat with breech plug length and hole depth are the same?

[AndyThomas]

Gary,

You'll have to take metal off both the breech plug (i.e., the very front part), and the back of the barrel. In essence, you're shortening the plug and the depth of the hole by the same amount.

I don't have a lathe, so I use files and a square. If the barrel has a taper use a sliding bevel for squaring the breech. It can be tedious. Use felt marker on breech plug to see if it's hitting the shoulder squarely. Once it's fully tightened, the plug should hit the shoulder evenly all the way around.

Hope this helps,
Andy

[Dave B]

You make the asuption that the stamping is on the right flat to begin with. I have found that my green mountain barrel had to have the stamp placed on the right oblique flat on my full stock mountain rifle. I breach the barrel and examine the breach internally. if its out of round you will be able to see it. I mice the muzzle to check for runnout. Theoretically should be none but there was in my case. I used prushain blue marking compound to paint the seat of the breach threads and file off the edges that show blue and file down the out side face of the barrel respectively till I hit my goal flat then make my witness mark. very straight forward stuff.

[Acer Saccharum]

I don't know what your shop is capable of, but I'll run thru what I do for fitting. You definitely need a lathe for this.

First, I make the plug exactly 1/2" from tang shoulder to plug face. Take that out of the lathe.

Then I set up the barrel so the threaded section runs true. I bore a shoulder exactly 1/2" deep, rethread the hole right up to the shoulder. Screw in the plug.

Oh, $#@*, it's 1/4 turn (2 flats) away from where I want it to line up.

Now comes the math part:
I am using 3/4-16 thread. That is 16 threads per inch. One revolution of the plug will move it in 1/16 of an inch (.062). Divide the .062 by 8 flats = .0078 per flat. So I want to turn the tang two flats to make it line up. (2 flats x .0078 =.0156") If I remove the .0156 from both back of barrel and shoulder of bore, I should have a perfect alignment. It hardly ever works out exactly. So if my math says take off .0156, I will take off .012 from each face, and try the plug. If I am within a 1/2 or a 1/3 of lining up, I leave that extra for a good wrenching tight fit.

Tom

[Stophel]

Lathe???

Well, you can put the mark on any one of the bottom three flats, which makes things easier.  Shoot for the first one, then if it tightens a little too much, you still have two more flats you can go to before turning all the way around again.

Trying to fit to one, specific flat is a real PITA.

[Dale Halterman]

On a pistol I made a few years ago, I didn't want to go to the trouble to get the trademark down.

It was a Green Mountain barrel with the trademark stamped in - no metal removed, so I tried to relocate the metal back where it came from. Tapped it lightly with a small ball pein hammer to get it mostly back in place, then used a small rounded punch to even it out as best I could. A little emery colth and you would never know it was there. The judges at Dixon's didn't notice it, either, although they did find a few other things they didn't like.

Dale H

[smylee grouch]

Thanks every one so far. I had one of those brain !@#$% this morning and remembered that i have some leftover barrel stubs and a few extra breech plugs so i will try a few experiments and see how it goes. Thanks again.

[davec2]

On the old board, I posted a tool I had made up for easily trimming a breech plug to length.  It could be used in a lathe (or in a vise and the length of the plug trimmed with a file).  For this type of situation, I use the original tool to trim the plug length and a blind hole tool to trim the breech plug shoulder.  You need a lathe for the shoulder trimming, but they both make trimming a plug so much easier as it eliminates all the normal set up rigamarole to hold  an already formed breech plug in the lathe.  Here is the old post    http://americanlongrifles.org/old_board/index.php?topic=198.0

Here is a picture of the tool used to trim the plug length.





This one is for trimming the shoulder



I use Acer's method of figuring out how much to take off and get close.  Then it's a little trial and error, but these tools make it easy to trim the plug putting it back and forth into the lathe.

[Acer Saccharum]

Yes, lathe, Stoph. The lathe has been around a lot longer than many people suspect.

[smylee grouch]

tricky business some times and different ways to get the job done the way it looks. I dont know that much about it but what would be wrong with removing one half the first thread going into the barrel if you wanted to go half way around, thus getting your breech plug into the barrel one half thread worth befor engaging the threads? Would this be tabo or unsafe?

[MSLitho]

Very interesting items.  Where/are they for sale?

[Acer Saccharum]

tricky business some times and different ways to get the job done the way it looks. I dont know that much about it but what would be wrong with removing one half the first thread going into the barrel if you wanted to go half way around, thus getting your breech plug into the barrel one half thread worth befor engaging the threads? Would this be tabo or unsafe?

Gary, some things come to mind:
a)don't start taking off threads if you don't have enough to begin with.
b) if you take off half a thread, you must also take off the same amount from the standing face of the plug, where it comes up against the barrel.( or whatever you need to take off to get the gap right)