I've hunted in Alaska for over a decade with a 270 and 308, after shifting away from a 338 win mag and 375 Ruger for big game. After seeing moose, brown bear, and caribou taken with much less powerful cartridges (223s are employed a lot around here), I just didn't see the reason to continue to beat myself up, and use more powder...I can load a lot more 308 than 375 using the same type of powder. If you're looking for one and done, 270 and 308 can serve you well. With that said, I've also taken caribou with a 223, and moose with a 243, which are MUCH lighter recoiling cartridges than you have, might balance out your collection, and are fun to shoot.