I can't understand why everyone seems to think the addition of a barrel nut is necessary to facilitate barrel swapping. The truth is, the barrel nut complicates things. Without the nut, headspace is fixed and you don't need to rely on a gauge. The advantage of the nut is only in play when chambering since there is no need to chamber to a precise depth. GD
I believe you've answered your own question. Without the expense and time involved in engaging the services of a craftsman such as yourself to fit/chamber a barrel to a particular action, a fellow handy with tools can more easily afford a half dozen barrels for his fun rifle.
