In a factory loaded cartridge......338 WM. Pretty darn efficient cartridge, recoil without a brake quite tolerable in a 9.0 pound package (scoped, loaded, slung), wide selection of components, easier on barrels than many of the "super" .338's, can easily be used out to 600+ yards. I know that my wife is pretty lethal with hers! It's her only rifle/cartridge, used for everything from Antelope thru moose/bear!
Most any big game cartridge can do the job. The .338 WM simply gives you greater flexibility. With good bullets, velocities, accuracy, component/ammo availability, long range performance, and capable of raking shots (with good bullets) on very large game (moose,elk, large bear) that should be passed on with lesser cartridges! JMO. memtb