Gunsmithing Shimming and torque issue, what would you do? 85 lbs and keep it?

[Long Range]

I'm having some bad luck.

Aero Precision 308 and a titanium barrel nut that needs to be aligned for rail screws. The barrel nut recommended torque is 35-80 ft lbs.

Here is what I did so far: and right now my barrel is torqued with 85 ft lbs and a .001 shim.

no shims = 90 ft lbs of torque to line it up
.001 shim = 85 ft lbs of torque to line up
.002 shim = 35-40 lbs to line up

What would you do here? Its also recommended not to re-use barrel nut shims and I can agree with that as they get messed up when you unscrew the barrel nut.

Would you keep it at 85 ft lbs? or do you think that I may damage something so high up?

I am kind of not happy with the 35 ft lbs using the .002 shim.

Would you possibly just remove the .001 shim and torque it up to 90 ft lbs? Get a new barrel nut or try .003 shims maybe?

Thank you for advice here.

 

[GH41]

What torque wrench. All but the best can be off 5# or more close to the upper/lower ends of the range. Are you turning the barrel nut socket perpendicular to the wrench shaft. If not you are reading less than what the nut torque actually is. You may have to draw me a picture... I seems to me like adding more shim would increase the force needed to line it up.

 

[Bradv86]

Why do you not like the 35-40ft lb option? Seems that you have it lined up while being in spec for torque value.

 

[Long Range]

Just seems too low at 35-40ft lbs no? I thought it was better to get higher?

 

[Rocketvapor]

Run it a few more times and the 85/0.001 will probably come down a little.

 

[Long Range]

What I did was, I had another receiver from Aero Precision that had a slightly more barrel sloppy fit, I could feel a little more wiggle in the barrel before torquing.

I used a .0002 shim in that one and was able to torque it to 65 ft lbs.

I guess I will see how well it shoots and then consider using shim stock. At least I know it needs a .0002 shim. A .0001 shim did not work with that receiver, I would have needed to over torque it.