People that claim the 257wby is to light for moose and elk and bears haven't shot many apparently. Of the 50+ head of game I've killed with one, I've never felt under gunned. In fact I've never even had an animal make it more than 5 yards after being struck by a 100gr tsx
You can kill a moose with a .223, but that does not prove a thing about it being adequate for the purpose just because you've done it. I've seen people kill deer with 22 magnums, guess that's a perfect deer round now? The .257 is a great cartridge if kept within its capabilities but if large critters are on the menu, opt for a better suited cartridge please.