I would not heat and action...how hot did ya get it? Enough to change the heat treatment of the action at a critical place, containing the high pressures. I've removed lots of difficult barrels. You need the correct external action wrench with the Weatherby cutout. I use plastic tape to protect the action.
An internal action wrench is not for taking off factory actions...but can be to install or use on switch barreled rifles, as too much pressure is needed usually, and action damage is a result. And in a few instances they have to be machined off, cut the barrel below minor thread dia. Small carbide boring bar, under cut the barrel threads all the pressure is relieved, spray on a little penetrating oil, and take off the action with with an external wrench, as sometimes a rust has formed in the threads of barrel & action of blued steel, and thread locker type adhesives may also be present.