It doesn't take all that much torque to crank the barrel over.
If you hold only the receiver, the flange on the barrel takes torque from the nut and transmits it through the pin to the receiver, SLIGHTLY distorting it.
If you hold only the barrel, torque from thread friction forces the receiver in the opposite direction. What is someone to do?
First of all, take it apart. Grease it up with the correct moly grease. Graphite and aluminum are a bad combo, the graphite attacks aluminum. Moly only.
Now assemble it hand tight. Center the rear sight and boresight it, making adjustments in windage turning the barrel to line up.
Now clamp the receiver in blocks. Get a drill press vise and use this to hold the barrel in blocks. I used hardwood blocks I made myself, coated with pitch rosin for extra grip. Once the barrel is locked from turning, clamp the drill press vise to the bench. I use Bessy Clamps but anything, including lag bolting, works.
Now go to town on the barrel nut to get alignment of the gas tube. Double check boresighting, you should be on the money.
Complex? Sure. Effective? You bet. Mine are within 2 MOA on windage, 4 clicks on the standard sight.
This method is also applicable to Savage 110s, only the issue is headspace. The barrel nut locks the barrel to the action, torquing it leads to decreased head space and can damage the chamber if done with a headspace gauge in it.
BTW, I am thinking of getting into this as a business. Send me the UPPER alone, plus $15 + shipping/handling/insurance and I will assemble within 2 MOA. Even test it, if desired and send the target in the return shipment.
Let me know. I am in San Antonio.