Barrel to action torque?

[Mram10us]

This was a piece of info shared by the Grizzly gunsmith, over and over again. In addition, when I retightened the barrel on the above mentioned 22-250 the .004 of excessive head space was eliminated. The barrel was essentially a little more than hand tight. BTY even after re-tightening it has never shot as good as it did before being removed from the action.

Interesting. I've never heard .004". Always heard the .0015-.002" of crush and that is what I've experienced. Thanks

 

[Sam Summey]

I have removed barrels from 1903 Springfields and 1917 Enfields that required in excess of 100 ft pounds of torque. One took a 4 foot long piece of pipe on the action wrench and I had to stand on the vise (to keep from turning the bench over) to break it loose. How much torque do you think it took to break it loose?

 

[Mram10us]

I have removed barrels from 1903 Springfields and 1917 Enfields that required in excess of 100 ft pounds of torque. One took a 4 foot long piece of pipe on the action wrench and I had to stand on the vise (to keep from turning the bench over) to break it loose. How much torque do you think it took to break it loose?

20inlbs?

 

[Sam Summey]

20inlbs?

It took about all of the power my scrawny *** could muster.

 

[Joefrazell]

So dumb question here. If the barrel was headspaced at being hand tight and then tightened down and moved .004" would the headspace likely be out of spec? How much of a window is there? Note: I will not shoot this rifle until the Smith goes over it and checks headspace. I'm just curious.

 

[Mram10us]

So dumb question here. If the barrel was headspaced at being hand tight and then tightened down and moved .004" would the headspace likely be out of spec? How much of a window is there? Note: I will not shoot this rifle until the Smith goes over it and checks headspace. I'm just curious.

Saami gives you .010" range for headspace. I think Most go /nogo gauges give you .006" of range, but don't quote me on it. Not sure if PTG, clymer, etc use the same .006" range or not. I know I've chambered rifles and had a PTG go gauge close but a clymer not close.

 

[Joefrazell]

Saami gives you .010" range for headspace. I think Most go /nogo gauges give you .006" of range, but don't quote me on it. Not sure if PTG, clymer, etc use the same .006" range or not. I know I've chambered rifles and had a PTG go close but a clymer not.

Ok that makes things alot clearer. Thanks a bunch

 

[Rflshootr]

Joe check your headspace with a fired un-sized case, or even better a brand new unfired case if you have one. Remove the firing pin assembly from the bolt, and while you have it out clean it and the inside of the bolt body, put a fired case in the chamber and the bolt should have no more then a slight resistance closing. If it is tight closing, then I'd definitely take it back for adjustment. Since you have a belted case the headspace measurement comes from the front of the belt to the bolt face. I try to set most barrels at minimum headspace to avoid case stretch and if that was done on your barrel, then with the re-torqueing it could have shortened by a couple of thousandths.

 

[J E Custom]

Bedding a rifle Is the last thing I do so there is no change in how it will fit. If I remove the barrel and the lug, the rifle has to be re bedded even though I use a fixture to hold the lug in the same place. Before loosening the barrel I set the fixture to hold the lug where it is, and then dissemble the barrel action and barrel.

I have also never seen a barrel need/loose more than .001 when all machining has been done right. I always set head space in the lathe to what I want for the rifles service (.0005 to .0015) and it stays exactly that 90% of the time and falls within .001 of what I wanted. If I predicted correctly it is exactly where I wanted it.

I use nothing but go and no go gauges to set head space and will not go beyond .0035
on any chamber. Many cartridges are maxed out at .006 and others are considered un usable at .008 head space you must use the proper No gauge to establish this head space for safety and case life.

Torquing must be consistent to arrive at these tolerances without trial and error. the size of the shank thread must also be considered, The smaller the shank the less torque it should/will take. and the thread pitch can also have an effect on the amount of torque needed. A little trick when taking a factory barrel or one that hasn't been put together with anti seize or thread lubricant is to use a rubber mallet or a hammer on the barrel wrench to impact the threads instead of taking a chance of twisting the action by using a long cheater on the wrench.

I prefer to use the amount of torque needed for the service based on the many other things mentioned. I have never had a barrel loosen if it was properly fitted and torqued using a thread lube or anti seize at 40 to 60 ft/lbs and removal has always required one or two hits with the 4 lb rubber mallet. (The rubber mallet has plenty of impact to break the barrel out without damaging the action wrench.

J E CUSTOM

 

[Sam Summey]

So dumb question here. If the barrel was headspaced at being hand tight and then tightened down and moved .004" would the headspace likely be out of spec? How much of a window is there? Note: I will not shoot this rifle until the Smith goes over it and checks headspace. I'm just curious.

In the case of the 22-250, the barrel was originally head spaced with the barrel tightened to around 60#ft torque (I did it.) The head space was not checked by the gun butcher who threaded the barrel for the muzzle break. I will make an assumption that the barrel was reinstalled on your rifle and not head spaced either. You wouldn't happen to live in Western NC would you?

 

[Sam Summey]

Owning and operating a skilled machine shop, does not a gunsmith make.

 

[Joefrazell]

In the case of the 22-250, the barrel was originally head spaced with the barrel tightened to around 60#ft torque (I did it.) The head space was not checked by the gun butcher who threaded the barrel for the muzzle break. I will make an assumption that the barrel was reinstalled on your rifle and not head spaced either. You wouldn't happen to live in Western NC would you?

No I'm in idaho

 

[Danny1788]

So dumb question here. If the barrel was headspaced at being hand tight and then tightened down and moved .004" would the headspace likely be out of spec? How much of a window is there? Note: I will not shoot this rifle until the Smith goes over it and checks headspace. I'm just curious.

.004" crush is ALOT I've never seen a chamber that I have cut shrink that munch when the barrel is torqued down. I agree with JE Custom on I normally have .001" to .0015" MAX crush fit when torqued down. I don't make my tenon threads super tight but I don't make them loose either. If your torquing a barrel and the headspace shrinks .004" I would be concerned about thread fit or something being out of square.

 

[Danny1788]

I will say if you have a torqued barrel and you have go gauge plus .004" as your no go. I would call that safe, anything over that I would cut the shoulder back to adjust Headspace.