I went for the M03 as I wanted a takedown, barrel swap system.

If I had a "hundred thousand plus" I would have had made a series of grand fantastic custom Mauser 98 takedowns. Bolt head differences would make this actually more limited. As would the magazines. The Mauser M03 magazines work. When the springs do .... waiting to see if my .222 mag is to be repaired under warranty.

I would much prefer a Mauser action where the actions lock up on a collar on the barrel, not the action. Removes some problems with barrel threads that can occur sometimes over time.

If I wanted a non switch barrel single calibre rifle, I wouldn't bother with a M12, M18 or whatever and why bother going past a Mauser M98 or a Mauser derivative action.