Lot's of good words in these responses.

I too wanted a .338 for a while and decided the .340Wby was the way to go. Great ballistics and great energy to as far as I'm capable of shooting and beyond. However, after having taken many different big game animals in the Rockies over the past several decades, I've found the KISS principle to apply to this issue as well. 30 caliber cartridges can, will and do take everything on the North American Continent. Many people believe the Bigger or Scarrier the animal the bigger your bullet must be. I tried the 200+ grain bullets for the 30's and used the 175gr for the .284's (7mm). I've now settled on the 150gr in my .300 Wby and have several friends who have done the same. My reason is, it works best out of my Rifle and the animals are just as dead. Never saw an Elk walk very far without lungs.

That being said, I still want a .340 Wby and will likely buy one. I like rifles that let you know they're there.