Leveraging the Laws of Thermodynamics to Remove a Stuck Barrel Nut

I picked up a nice free float rail from ALG defense, so I needed to take the barrel off of my Palmetto State Armory (PSA) mock dissipator. Sounds easy right? Well not so much. Using my improvised upper clamshell and multi-tool I couldn’t even budge it. I managed to lift my workbench slightly off of floor in the process. This was pretty impressive as my workbench is a couple hundred pounds and screwed to studs in two walls.

The front sight was canted so I knew it was probably over torqued but it was worse than I expected.

After a few more tries and a can of liquid wrench, I gave up and ordered a torque bar and a heavy long handled PRI barrel wrench.




Even with the new tools ,the barrel nut wouldn’t budge. Before I broke out the saw I thought I’d give a trick I read about a try. Science suggests steel (the barrel nut) contracts less than aluminum (the receiver) when frozen. So I tossed the whole upper in the freezer overnight with the jäger and my wife’s homemade Popsicles.



Luckily that was just enough to break the nut free and was able to move on to installing my ALG rail, which was much easier.


If I were to do it again I would have ordered the more expensive geissele reaction rod as it has nice flats built into it. The flats would make it a little easier to work with.