Breech plugs and swamped barrels

[Blacktail]

I've been trying to screw my breech plug into my swamped barrel to get the witness marks to line up. Either my vise totally sucks or there is some trick to properly shimming a swamped barrel in a vise. My vise is a 4 incher, a machinists vise I think is the proper term for it. I tried shimming it with various combinations of rubbery plastic jaw liners, leather, pine, and cedar.

My first gun was a parallel octagon near the breech, so I could really torque the vise down on the padded barrel and get things done. Not so simple now! What does everyone like to use for shimming swamped barrels? I was thinking of using JB Weld to make some vise blocks. Would this work?

[Rich]

I use a 5" bench vise ( because that's what I have) and line the jaws with sheet brass. I mount the barrel vertically in the vise. Make sure you have some wood on the floor under the barrel so that if the barrel slips, you don't ding the muzzle. I've tried leather and wood lining but both allowed the barrel to twist. The brass doesn't. 

[rsells]

I made a couple of .100 inch pieces of brass that were formed to fit the top of the jaw and inside of the clamping areas of the chuck jaws that I use to work on barrels both swamped and straight.  There is a tool that I have seen at the CLA show that  is used to clamp swamped or tapered barrels in a vice, but I have never invested the money.  I can't remember who was selling the tool, but he is against the right wall inside the main room at the CLA show in Lexington.  Some of the other folks may know who this guy is.  The tool looks like two triangles (wide base and short in height) connected together to form a pivit point at the top of the triangles.  It is set against one side of the vise and close the other jaw against the barrel allowing the inside part of the tool to conform to the angle of the barrel and push it against the vise evenly.  
                                                                                    Roger Sells

[KentSmith]

I clamp the barrel vertically in the vise with the jaws wrapped in a couple of lead strips.  Brass works too.  I use an old pipe wrench again with the jaws wrapped with lead.  It's the only thing I use the wrench for.  Everything works pretty quick.

[rick landes]

I like to use 1/8 strips of alum. These grip fairly well and do not seem as "slippery" as the brass. Apply vise pressure close to plug, do not over torque vise or you can pinch plug threads.

[Dale Halterman]

I use aluminum like Rick, but mine's a little thinner.

Dale H

[rich pierce]

It doesn't need to be that tight. In my estimation, many breech plugs are too tight.  Sometimes removing a breechplug is like getting the lug nuts off a front wheel after the guy at the tire place used an air gun to put them on.  Lots of times the threads are not bottomed completely and the last 2 threads on the plug are binding.  Since this actually prevents getting the breech plug face to butt up against the breech, the tightness is giving a false impression that everything is really close in tolerance.  To fix that I blacken the plug with a felt tip pen and turn it in, then dress the threads as needed with a needle file.

[Benedict]

My machinist vise is a 4" vise that I have installed maple jaws on.  the jaws are interchangable with the metal ones but I use the maple ones for 95% of my work including removing and installing breech plugs.  The maple does not mar the barrel and seems to give enough the grip the swamped barrels that I use exclusively.

Bruce

[keweenaw]

The barrel I put the plug back in yesterday couldn't have been done in a 4" machinist's vise but was no problem in my regular barrel vise.  I prefer using strips of oak for padding the barrel in the vise, no matter what type of vise, to the use of metal.  The oak will crush a bit and take up the taper in the barrel and is hard enough to not split when you try to turn the tight plug in or out.  Ideally you should take so strips about as WIDE as your jaws, clamp them together and drill a hole about 3/4" in diameter at their juncture so the hole goes across the grain. (Two boards stacked on top of one another drilled across.)  The round hole will conform to the octagon on the barrel as your tighten it in the vise and give much better resistance to rotation than the use of plain, flat sheets of anything.

Tom  

[Blacktail]

Thanks for the ideas! I will try things out and let everyone know what worked for me. One more question though...Do most of you mount the barrel in the vise vertically like Rich, or horizontal?

[Dphariss]

Breech plug need only be turned in with moderate pressure with a 12" wrench.
BUT.
If its not properly fitted it will tend to turn in too far.
Coat the threads and other bearing points with STP engine treatment and reinstall you might be surprised. You really need some lubrication even chassis grease will work but I like STP.

You need a bigger vise too a 4" in pretty weak unless a really pricey one but a heavy 6" is a lot better. I use my mill vises for barrels.
You can make blocks of hard wood too. I used to make a lot of blocks and such from 1" or thicker aluminum but my source for small pieces (6-12") dried up.
Just be sure not to over squeeze the barrel.
Dan

[Randy Hedden]

The secret to working on a barrel in a vise without the barrel slipping is to create three or four points of contact between the barrel and the vise jaws. To do this make your self a couple of hardwood 45 degree "V" blocks to mount the barrel in before tightening the vise. Usually if you use one "V" block and something to pad the other side of the vise you should have no problem with the barrel spinning in the vise. Two  blocks may be overkill, but will work well in the vise.

Three or four points of contact with the barrel will assure that the barrel will not turn in the vise. It is also a good idea to lubricate the breech plug, but remember that when you go to put whatever finish on the barrel there will be a place where the lubricant has seeped out of the crack between the barrel and breech plug where the finish might not take. You will have to completely clean the area to prevent this from happening.

Randy Hedden

www.harddogrifles.com

[Dennis Glazener]

One thing that I didn't see mentioned is to be sure you are not clamping the threaded area. Back away from the breech the length of the breech plug threads.
Dennis

[Blacktail]

I forgot to provide some info: The barrel is a Rice .58 cal. It arrived with the plug screwed in, but not tight, and well covered with copper colored anti-seize compound. I examined the plug and found it to be lightly polished, it has some light file marks seems to be fitted, but that's one of the things I was trying to accomplish. Should I put some other stuff on the threads?

[keweenaw]

The antisieze is all you need on the treads.  The one I had off yesterday was also a Rice.  It will go back to the index marks if you use a big enough vise and wrench.  Don't put it in the vise vertically as you get too little clamping area on the barrel to prevent it turning.  If you can get it close to alignment and the barrel isn't turning, you can drive it up to alignment by rapping on the end of your wrench with a lead hammer.  And no it doesn't need to be that tight but it doesn't hurt anything if it is.

Tom

[Ky-Flinter]

Blacktail,
I mount the barrel horizontally in the vise with the breech end positioned so that I'm pushing down, not pulling up.  And leave a little sticking out, so you aren't compressing the threads (Thanks Dennis).

For clamping swamped barrels I made up some tapered shims out of brass sheet stock.  I cut some strips 1" x 4", 1" x 3", 1" X 2" and 1" X 1", stacked them up with a dot of superglue between the layers.  Like this......
 ___
 ________
 ________________
 ________________________
 
-Ron

[Blacktail]

That's interesting. How thick is the brass you use?

[Dr. Tim-Boone]

1" Oak V blocks hold it in the vice well!! Pushing down is good!!

[Ky-Flinter]

Blacktail,
My apologies, my memory ain't what it used to be.....  it was 3 layers, not 4.  Sheet stock is .016" thick.  Makes up .032" per side... about right for a 38" Rice B.

-Ron

[B Shipman]

I'm with Rich Pierce on this one.  If you can't turn your plug to the witness marks easily with a 4 in. vise  (a little small, but's that's what you got) shimed with brass or something else, it's a jam fit. Rice barrels are one of the best in getting the plug to the shoulder but even here there's some jamming. I go back with a bottoming tap ground to full threads, and this usually solves the problem.


P.S. This is necessary on Green Mtn. barrels. They aren't close to getting full threads to the shoulder. Not close. Great barrels other  than that.

Tight does'nt require force- just the opposite.

[Blacktail]

Got it! I don't have any brass or aluminum scrap around, so I tried Snyder's suggestion.

After measuring the outside diameter of the barrel at two points near the breech, I cut two pieces of 3/4" thick oak stock 2.5" wide. I then clamped them in the vise and drilled a 1" hole in both, so that each piece made up half of the hole when they were joined. Then I did the same thing with a second, but made the hole 7/8" instead.

I found that the easiest way to get the whole deal in the vise was to first secure the wood blocks to each other around the barrel with masking tape. The 1" went slightly forward of the plug threads and the 7/8" went about 3 or 4 inches further down. The wood compressed perfectly and got a good bite on the barrel. After a couple taps of thump therapy with a rubber mallet to the end of my wrench, the witness marks were all lined up.

The oak was a great idea. It scrunched up good, so much so that I had to lightly tap the blocks off the barrel with a mallet. I think pine or somthing similar would have just cracked and let go. That oak is good stuff. Thanks again boys!