28 Barrel Issue

[bug]

A friend contacted me about a problem he's having with an early (27K) Savage 1928. When he fires the gun and it heats up, the barrel backs out about 1/8". He noticed that the front sight was moving out of line and discovered the issue. While the gun is still warm the barrel can be returned to the starting position. When cooled down the barrel is tight. Not a good situation. Any thoughts?

 

Bob D

 

PS I have not seen the gun in person.

[laurencen]

seems it needs tightening, maybe when warm, the marks will likely be off but should not loosen when fired

[buzz]

it sounds like the barrel is only a little more than hand-tight and the combination of being heated and vibrated is making it unscrew.

 

Maybe it was marginal all these years and strain relaxation of the steel finally ate up all the factor of safety in the barrel torque.

 

A barrel vibrates violently when a bullet is fired, just like a tuning fork. That's plenty of energy to unscrew a loose barrel. Vibration is a big problem for threaded parts. That's why there are no screws inside any guns.

 

If you shoot a MAC10 with that big 2 stage suppressor on it, no matter how much you tighten it, the vibration will make it unscrew. So you have to hold it with your hand.

 

Sounds like a job for recon bob.

 

maybe he can scrounge up a new barrel that snugs up properly

Edited April 20, 2015 by buzz

[TD.]

I agree about the reconbob solution. After the barrel backs out 1/8" is it possible to unscrew it completely? It should be easy to unscrew once it is loose. If so, I would remove it and have a look at the grip mount. While the grip mount does not hold the barrel in place, it is possible the grip mount has failed and is contributing to the problem.

[reconbob]

The barrel is too loose. Obviously this should not be happening. The bullet pushing against right hand rifling is going

to torque the barrel to the left, so it should not unscrew. Perhaps the barrel is shot out. The fix here is to remove the

barrel and clean the threads in the receiver and torque the barrel back on...BUT, now the front sight will be a little too

far to the left (as you sight the gun). So the comp will have to be repositioned. BUT, if the comp has only been turned

a very short distance to bring the sight back to top dead center then the existing hole for the pin will be run into with the

new hole and the pin will probably not be tight and the comp will not be tight.

If it was me I'd replace the barrel with a new MINT original barrel, torque on properly, and repin the comp. Since its

a MINT barrel there will be no cross pin hole yet and everything will be tight and correct.

 

Bob

[jim c 351]

Bug,

If the barrel moves at all, then its not properly torqued, and it is not likely the original barrel.

We are absolutely sure that its the barrel that unscrewing and not the comp unscrewing ,---aren't we????

It was probably installed by someone lacking the proper wrenches to get the proper torque.

When you find someone with the proper tools , then the front sight will be off and that will have to be corrected.

The original barrels are torques unbelievably tight. They never come loose.

Best of luck.

Jim C

[StooperZero]

i had an auto-ord M1 semi about 10 years ago when It warmed up the barrel would start coming out. At the time i was LIke "screw this junk"

Shoulda kept it , would have been an easy SBR rebarrel after 100 rounds or so. ** my brain at the time turned down several Under $7K west hurley guns too. **

 

oh well.

[GUTTERRATT]

Tighten the barrel. There is no torque spec that I am aware of so get it tight. The only problem you might encounter that you might need help with is your front sight index if it changes. Edited April 20, 2015 by GUTTERRATT