Arguments never end about which cartridges are adequate for the hunting of elk. Nobody has ever said, however, that a bullet fired from a .338 Win. Mag. lacks enough power for that task.
A pair of quality optics changes the big-game game, as the human eye's ability to see objects clearly changes over time.
The magnum cartridge craze was at its height about 40 years ago and, at least for the author, stood idle for the past decade.