The action wrench locks onto the front of the action using a bolt in the front action screw hole to prevent any slippage of the receiver, so there is no torque to speak of on the action. The simple way to pop the barrel nut loose is to attach the action vise and while standing on the handle of the vise, step on the barrel nut wrench. The nut wrench should be positioned so that it is barely off the floor. It will pop loose without much effort.

My first barrel swap was using homemade barrel blocks and a barrel nut wrench. I will not go through that again.