If you take everything out of the bolt so you have good feel, I find I can set the headspace to within one thousandth using fired brass.
If you want to switch things around a lot, you can red loctite the barrel nut when you first install the barrel. From then on you can use it like a shouldered barrel to get consistent headspace. I have been doing this with a few Criterion Savage prefits on a TL3 for awhile now. If you want to remove the barrel nut from the barrel, a little heat will allow you to spin it off.
Edit to add: If you use loctite, grease the hell out of the action threads and try to keep all of the loctite off of the action.