Yes there's something very appealing about the .375 flanged, but ammo availability is not good and it would have to be regulated with something. Norma load it in their PH range with thick jacketed bullets and I believe Kynoch do, but I think that's it over here.

9.3x74R is widely available with multiple loadings available from RWS and Norma. It would also be the right caliber for a German gun.