.400 Whelen IMP would be a better suggestion, 93x64mm.
The IMP case is much easier to work with and has no headspace problems, headspacing being controlled by the .454" (to .460") shoulder very nicely.
I only included the .460" number as that is what my .375/06IMP has, along with a .470" base.
Even though a Mauser action, it operates with as little muscle as my little finger provides on the bolt. snick - snick - 270TSX at 2,650fps.
The .400 Whelen IMP would make an excellent round for that rifle, ihmo.
A side mounted aperture sight, with a round brass or ivory or Sheard gold bead front sight - perfect!