After a couple times a blind monkey could swap barrels
I have 4 barrels for my model 12 and change over in a couple minutes, one barrel is shouldered and the rest are nutted. Action is bedded only so changing over makes no issues with that.
Some set the head space with a case but I find it much easier to do it as geargrinder said, spin down on the go-gauge and tighten up then check with with a piece of tape then rock on. I don't tighten my barrel nut tight enough to need the action wrench, I just hold the barrel in one hand and give the wrench a wack and it spins of except for the shouldered one.
If your identifying a large shank by the step the varmint barrels also have a step.