I bet the rifles could be rebarreld. Looks like a shrink fit no different than a gear on a shaft. Bet they use induction heating on the receiver and just slide a cold bbl in there. Should come out about the same way. The tolerances needed for a good fit must be very high, bet bbls are ground rather than turned on a standard cnc. Were talking within .0002 as a guess??? that's die and gauge manufacturing type specs.
Its a Total guess, but after seen Ardents 202 takedown thread and how that gun simply fits together with no fasteners it seems obvious Sauer has absolute top of the industry manufacturing equipment and capability's. Remember that gun holds the bbl in place with a simple friction fit not even a shrink fit and not even that much friction if it can hold its zero its nutz