Especially because I have more suitable rifles for this purpose in my gun safe.

Based on my personal experience and after I have shot buffaloes with various cartridges caliber 9.3mm to .510 , often without an PH for the backup , I am of the opinion that DG should be hunted with much larger calibers than with the cartridge 9.3x64 Brenneke or the cartridge 375 H&H Magnum. The latter are good cartridges for hunting plain game in Africa and can be used to a limited extent on Big or DG if necessary , but not as a first intention.