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Rebarrleing / How tight?

wonderwolf

Aluminum
Joined
Jan 10, 2007
Location
Ohio
I've worked on some guns at my home shot that are very easy to pop the barrels off of. I've heard that with some Remington rolling block barrels some can be removed almost without the use of tools. I have a 1919 belt fed that simply threads in and you can adjust the head spacing on as well these are the kind of intalls I'm used to.

I've seen target rifles that have fairly loose fitted barrels that don't require the use of a extremes to remove them. I have a .243 I'm building on a mauser action and I'm just wondering if I need to get a weight gauge to tell me how much torque I'm tighting it down to or what? I have yet to pop the old barrel off the action yet as its soaking in kroil as we speak. I havn't had a chance to look anything up on the subject in any of my gunsmithing books yet as I've been everywhere but back at home.

Also. The barrel I got is a very thin (at least to me) sporter barrel. I'm almost wondering about turning down the barrel and sleaving it in another barrel I have that Is shot out Has this been done before? I know its like the opposite of putting a liner in the barrel but? My only concern is the amount of stress it would put on the barrel. I know hatcher turned down 30/06 barrels till they had a wall thickness of 1/8" at least back to the chamber and he didn't have any problems.
 
I have never turned a barrel down to use as a liner, so I really can't comment on that question. I have installed a lot of Mauser barrels, however. I use an action wrench about a foot long, and I typically bump the handle with around 50-75 pounds of weight when installing a new barrel. I do that several times in the process, so that when I seat the barrel the final time, I know that it is screwed all the way home.

Sometimes removing the old military barrel can be an adventure. Kroil is absolutely the best penetrant on the market, so you have things started in the right direction. Use rosin on your vise blocks, cinch them up tight, and use a cheater on the action wrench handle. If it won't break loose, use a hammer on the wrench handle. Often a sharp blow will get things moving when brute force won't do it.

Good luck!

Clemson
 
I know Hatcher turned down 30/06 barrels till they had a wall thickness of 1/8" at least back to the chamber and he didn't have any problems.

While this may have worked for a few shots, I am sure that it would have failed catastrophically from fatigue had it been fired anything approximating the normal number of shots a barrel is expected to endure. It is an interesting experiment but not something to be used as a model for normal activities.

Regarding barrel tightness, I tighten mine by setting the barrel in the vise such that the action will tighten when the wrench is rotated to between 5 and 6 o'clock. Then I set the wrench straight up and tip it over such that it falls toward tightness. When the threads mate, the wrench stops rotating and its kinetic energy/angular momentum are used to compress/stretch the steel, giving the desired amount of tightness. Easy to do but I can't give you a torque wrench reading from it. I suggest that you do it several times before the final time so that any minor deviations in the preparation have had a chance to be ironed out.
 
I have had barrels that just would not come off without destroying the action. I found that if you grind a cutoff tool thin and with the barreled action in the lathe, cut the barrel as close to the action ring as possible to just the minor dimension of the thread and the barrel will spin off by hand (most of the time). The barrel is saved so it might be used again if necessary.
 
Well the absolute worst barrel to remove from an action was a Thompson SMG. I had to really heat it up to finally pop it out a 12ton press was used just to hold the action tight enough. I've found a electric heater helps after a kroil soak in poping the mauser barrels right off.
 
The worst of the lot seems to be the XP-100 barrels, they must use super glue on em..
A good heat gun will sure help out a lot melting down some of the stuff they use to keep em on.
Kroil is also a needed plus..
I've never heard of any set torque values for seating a barrel, but after screwing it in tight by hand a few times, I hit the 12 inch install bar once with a 5# block of lead to seat it...
Never lost one yet either..........
 
Hi There,

I work on some Mausers and I like to have the barrels tight. I machine the breach face
and shoulder to contact the action at the same time. And then when tightening, I turn
the action another 5 to 6 minutes or so (if you view the face of the action like a clock dial)
passed the contact point to get the desired compression.

Good Luck!
-Blue Chips-
Webb
 
The worst of the lot seems to be the XP-100 barrels, they must use super glue on em.

I've done a couple of XP-100's but I can't remember if they had Loc-Tite on them or not. I did encounter Loc-Tite on a Browning 78 and a Ruger Mini-14. Both were real pains to break loose.
 
Remington definitely uses something on their barrel threads. Whether it's super glue, loc-tite, linseed oil, buzzard snot, or what, I don't know. When you run into one that won't budge you can chuck the barreled action in the lathe and, like Tony said, make a thin cut, but instead of the barrel make the cut in the recoil lug. The barrel will pop right off, the barrel will be untouched and all you need is a replacement lug. Most gunsmiths who do rebarreling have a drawer full of lugs and they will probably give you one for a cup of coffee.

Ray
 
We tighten them by hand, give them a firm snap by hand then tighten them 5-10 degrees further. Most companies overtighten the barrels or add locktite to the threads due to the lawyer issue.

The problem is that if you start overtightening a barrel, as was stated already, you weaken the structure and you can impart energy into the barrel causing accuracy issues.

On our quick change barrel guns, we put a tick mark on the barrel and the action to resolve any question of proper torque.

Mike
 
The minimum torque should be 25 ft-lb., assuming good machine work(this is from vibration experiments I ran years ago). If in doubt, use more but I never go over 40-50 ft-lb. It's really not that critical.
 








 
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