BARREL TORQUE

[Link]

If you tighten PFT you could stretch the chamber to a Magnum length?

;]

 

[Luisyamaha]

I use 40 ft/lbs for a switch barrel rifle. BAT action, Kreiger barrels.

Luisyamaha

 

[Dgd6mm]

I took a shouldered Kreiger off a Savage target action today with my action wrench. I bought it from a Gunsmith that built it for himself. A quick snap of the wrench and it was loose.

 

[dcali]

Speaking of Harold Vaughn’s book, this is one of the few things in it I think he got wrong. While everything he says about threads and torque makes sense, and he makes a good argument that there is some slight gapping, his conclusion that it matters flies in the face of benchrest shooters using much less preload. (By the way, the Teflon tape is for lubrication, if I recall correctly. He was going way out of his way to get as much preload on the threads as he could). My guess is that threads are basically conical on some level and serve to center the barrel. Also, a properly set up action will have a square face, which means any tiny misalignment will not show up on the target unless it impacts vibration. But it’s tiny at best, so... I think he was barking up the wrong tree.

The other thing I know of that he wrote that’s wrong was the equation that shows the size of aerodynamic jump. He uses an equation that FW Mann came up with over 100 years ago. Mann was wrong. Read Mann’s book, by the way. It’s outstanding. I’m not sure why Vaughn put that in his book. I’m sure he knew better.

Also, don’t use the machinery’s handbook. Those specs are for generic bolts when you haven't done a proper analysis (that is, typical values for non-critical joints). Rifle barrels are a little different. Although this brings up another point that nobody ever mentions - barrel threads aren’t all the same diameter, so the same torque isn’t going to preload them all the same.

Long story short, I think shooters overuse torque wrenches. They’re not as useful as we think.

 

[Tommie]

My technique was first developed as a teenager while working on hotrods:
Tighten till it strips, then back it out a quarter turn.

Have a nice day!

 

[Dusty Stevens]

My technique was first developed as a teenager while working on hotrods:
Tighten till it strips, then back it out a quarter turn.

Have a nice day!

You sure you want that done to your guns?

 

[D Coots]

If you want to exercise your eyes on theroies on a cold winter day, read Vaughn's book.

If you want to learn to shoot better, read Boyer's book. He is unreputably the best short range shooter in history. He's forgot more than Vaughn ever knew about competitive shooting.

Later
Dave

 

[Dgd6mm]

How about, 40 lbs and Hobo oil as a lubricant??

 

[Uthink Uknow]

I think the question of how much torque goes back to what the manufacturer says about torque on his action and it goes back to how the action is used. I think.