The AR-15/M16 barrels and bolts are made to such a standard that having to swap bolts or barrels to find one that works very rare. The need to check headspace really comes about in heavily used military issue rifles, to gauge when they are approaching "worn out".
With new bolts and barrels, it is not a problem. I have never seen a headspace problem with any AR-15 in any reasonable condition.
If it was SOP to have to swap around bolts and barrels to obain proper headspace, then AR-15's would have to cost WAY more than they do now.
It is funny, half the guys here are worried about headspace, and the others gripe about "tight .223 SAAMI chambers" w/ 5.56 NATO ammo causing kabooms. (I am still looking for any documentation of an actual kaboom from this.)
In short, don't worry about it.