Geissele reaction rod?

[doctorjj]

White Oak Armament recommends greasing the shoulder of the barrel nut where it contacts barrel extension to avoid shearing the index pin.

I always do that anyway but doing that doesn't fix the fact that with a reaction rod you aren't directly holding one of the two things you are tightening together.

 

[HiredHand]

TM shows the barrel being clamped in a vise while the barrel nut is being installed on the receiver.

 

[doctorjj]

TM shows the barrel being clamped in a vise while the barrel nut is being installed on the receiver.

That's not the best way either.

This is just one of many threads about shearing an index pin. The discussion goes to reaction rods and their propensity to shear the pin. Holding the barrel, whether by a reaction rod or clamping the barrel isn't the best choice for R&R barrel nuts.
https://www.ar15.com/archive/topic.html?b=3&f=66&t=654549

 

[Sanford]

Don't doubt a pin can be sheared or the receiver slot stripped but think it's going to take far more torque than I'll ever apply; I've never needed to get close to max yet. Appears most problems happen when removing a barrel, for that penetrants and heat do wonders ... but maybe I've just not encountered the one that requires the four foot cheater yet.