I use about the same 120 ft/lb for my centerfire guns but only about 60 for my Rimfire BR guns...Actually there are some guys who are constantly swapping barrels who only hand tight them (no extractor slots), I like mine a little tighter because I cut extractor slots.
Had a smith tell me to put anti-sieze on the threads, lightly, and run it up tight to the action. Then he said to put a good action wrench on it and give it a good tug. Said that was enough. I've done it that way ever since. No problems. He also said there was no magic number, just a good tug and your done. He's a hall of fame BR shooter as well as a smith.