There's also over 100 years of experience in making .375 projectiles kill very deadly and tough things. If you're not married to the suppressor thing, a .375 H&H or .375 Ruger will just stomp the shit out of everything short of elephant and cape buff while still being tame enough for most shooters. good for deer too, not much meat damage with a .375.
.375 Dangerous game ammo was used for it's armor piercing qualities in the first and second world wars too. a lot of dangerous game projectiles have steel cores or steel jackets covered by a secondary copper jacket. fun fact.