Jerry;
I fail to undertand this last post. How can you "Open Up" the Sauer chamber to the standard one when the Sauer chamber is larger to start than the standard??
Were they speaking of opening it to the 9.3x74R round. Not sure I would want to do that, that round is close to the .375 Mag in its loading intensity.
I havent checked out the dimensions but that might be a possible source of brass for the Sauer round.
Note that J P Sauer & Sohn probably made a lot more guns in the standard 9.3x72R chambering than they did their own proprietary one.
The Standard 9.3x72R round was developed in the black powder era & saw long service. I can't really confirm this but have read that later Smokeless powder loads of higher intensity were purposely made so they would not chamber in the old black powder proofed guns. Seems this was said to have been done by using a thicker rim on the Smokeless shells.
The black powder 9.3x72R was in about the same class as a BP .38-55 while th smokeless version is close to a .35 Rem.