what am I doing wrong (this time)?

[bjmac]

I am building a Hawken in .54 cal. All of the parts were ordered from Track of the Wolf at the same time. I had their gunsmiths install the (cast) breech plug. The tang (also a cast part) fit was way off - on the order of 1/16th of  an inch (top to bottom measurement). I flattened the tang face on a granite machinist block (Measured at +/- .003 in) so it is now flat and square. Now I have narrowed the gap to about 1/64 ", but the tang rocks (up and down). I keep taking the square and cannot see where the "hill" is. So my actual question (finally) is: How on earth do I get this sucker flat and mated? The milling machine that I am using is the old fashioned one---files, hands and eyeballs..
 Any ideas to help me get out of this (new) mess?
 Thanks,
BJ

[Frenchy]

I would paint a very light coat of "Prussian Blue" on the standing breech face (tang face that the breech plug fits to), install onto the barrel (breech plug),
carefully remove it. The Prussian Blue will leave a spot of color where it contacts the breech plug. That is your high spot that needs to be removed. Continue until you
have the fit you are looking for. Probably requires reworking the hook as well.

[rsells]

I do similar to Frenchy with the exception that I use a lamp to soot the hooked breech, assemble the tang on the hook/breech area, remove the tang and look for the bright spots on the hooked/breech area that indicate the area that is making contact.  It is a slow process that takes time to complete.  Good luck with your build.
                                                                                             Roger Sells

[Kenny]

BJ, I have never worked from a kit so I propably shouldn't b saying anything, BUT, I do know about   fixing other peoples f#@%$$&  up`s.. ( in residential housing`) Think outside the box, is their`e blank worth the effortt??? sounds like the finished produ ct might be worth doing your own, just saying...

[Kenny]

BJ, once you get the tang to fit, any play underneath can be fixed with epoxy bedding....

[Bob Roller]

Take a closer look at the breech plug mating surfaces.I have had trouble with these and have seen exactly ONE that was right and it was the one Don Brown sold with his Alex Henry kits.I still have one and it is a fine piece of work.I am thinking most of these current plugs are made from waxes injected into poorly made moulds and then sent to a foundry.Don Brown spent a bundle on the Henry parts and it paid off.
Be careful with files and use one with a safe edge when trying a right angle where the plugs extention goes thru the tang.

Bob Roller

[rich pierce]

If you are experienced working metal with a hammer (black smithing) consider peening it into a good fit.  I think we forget our gunsmith forefathers were pretty handy around the forge.  With the barrel and standing breech vertical in a good vise and a helper to hold the tang in a vise grip padded with lead sheet or leather, you should be able to use punches to good effect.  Sometimes stock removal won't work.

[Dphariss]

These breeches are generally cast (and not all that well in some cases) to go together with little or no fitting so they are too loose and this WILL effect accuracy in the finished rifle. Bent or distorted waxes are a major reason for off center tangs, wrong curvature and such. These things can be a major PITA since there is apparently little care taken in casting the things.

Like Rich said. Do some peaning. Or have the "hook" welded up with a gas shielded MIG, not a TIG or you may be VERY sorry. Have just enough added that it will clean overized by .030 or so then recut and fit to the hole, that surely needs to be cleaned up before fitting.

This is one reason a Hawken is a "complex" build.

Dan

[Dphariss]

It is conceivable that you could screw it up till its scrap. Its  called learning. Learning is almost never free in gun making. But as your knowledge and skill increases it get cheaper. If you have a skilled maker in your area this might be a help as well.
If you DO reshape the hook after welding make some files with square completely safe edges. IE grind ALL the teeth off the edges and keep the ground side as square as possible. Not doing this will cause more work. Even three squares need the edges "safed" for most of this work. Though a dovetail file comes in handy in spots.
If the breech is slightly larger than the barrel it can be peaned to close some gaps but its best to have the full surface, as much as possible, contact with the standing breech face which also needs to be filed flat before fitting.
When done the fit to the standing breech should look like this

Not the dismal looking things found on most mass produced stuff often seen in pawn shops and such.
Yeah its a lot of bother but its difficult to get accuracy from a poorly fitted breech and even the better jobs often do not shoot as well as a fixed breech will.

Dan

[Acer Saccharum]

Dan, you keep showing your breeches to everybody. 

That's a great job on that breech. It's a highly evolved system, near the end of a long line of improvements. Look at the underside of the pan cover. There is a little knob that covers the touch hole when the frizzen is shut. If one puts too much powder in the pan, the touch hole is cleared simply by closing the frizzen.

The recessed breech face gets the pan a lot closer to the main charge.

When I grow up, I want to make one of these breeches on a target gun.

[David Rase]

BJ
Here is a link to a post by Curtis.  In it he manufactures his own hooked breech plug.  I recently made my own hooked breech plug because I could not find one available for a 7/8" barrel.  I had a 1' flint hooked tang in the shop which I fit up to an aftermarket straight tang similar to what Curtis does in his tutorial.  Hope this information helps or at least inspires.   http://americanlongrifles.org/forum/index.php?PHPSESSID=oa6lomnttji4chmaat1102gdi5&topic=27959.0
David

[Don Getz]

Bob........I also had a Don Brown kit.    When I got it I thought the breech and tang were soldered together until one day I bumped
it and it actually move a little.    He had to spend a lot of time fitting those things, you could not buy a better one...........Don

[westbj2]

You may want to do it this way if you have a traditional double radius hook.
Have a good look at the hook on the rear of the breech plug, be sure all surfaces of the hook are square with the top of the barrel and to each other.  All parting lines and irregularities should be filed off.  Look closely at the upper corners of the hook, you may want to ease these slightly.
Then from a piece of 1/16" thick piece of steel or brass make a template copy of the hook and the rear of the breech plug.  This should be a straight line with a hook protruding when complete.
Now you can insert this template into the standing breech hole and slide it left and right.  If the template is accurate, it will indicate straight away where the interference is in the hole.
If you have one of the breeches with a Thompson Center like hook......good luck.
Jim