Ian says yes. Their starter threads are timed in the exact same spot on all actions, nominal headspace. This allows prefits with the extractor relief cut in the tenon. There will still be some measuring and prob a dummy tenon for indexing required. I personally wouldn't go about prefitting this action myself but it's capable. I'm sure a cnc program could be written that would nail the tenon and relief cut every time.
Threads stretch/move with torque cycles. If a guy were to say have a rifle built in 6cm for hunting, then have a practice barrel cut in 6br. After say a dozen barrel swaps back and forth, at what point in time will the extractor cut start to get off timing at the same 100'/# tenon torque? Perhaps this action as a switch barrel might not be a good idea?
I know when my smith times his barrel markings, just a few cycles of barrel swaps, the markings have def moved from their original position, this doesn't matter as they're not cut for an extractor relief.
@Imac45acp can you shed any light on that? Is it possible to test that concept? How many times of making and breaking the barrel to your recommended torque before the claw ectractor is no longer inside the relief cut?