If your talking about all those big game animals stick with .30 caliber or larger. Really it all comes down to shot placement . Learn the vital areas of whatever your after. As mentioned the .325 wsm and .338 are great cartridges.The .375H&H is overkill for mostbig game in North americaand you dont need all that power unless your after big bears like grizzlys. But it will do the trick for sure with minimal if any tracking if you want to shell out$65.00 or more for 20 shells, and have a large enough frame to handle the serious recoil. The 30-06 has relatively light recoil and has taken every big game animal in North America as well. Best of all you can find ammo for it anywhere. Everyone stocks it.Bullet weights range from 130 grains up to 220 grains with both pointed bullets and round nose bullets. It all boils down to personal choice and what you can shoot well.