Are you asking about the 308 Win, and 270 Win????? There's a lot of 308's out there includeing the Norma mag for instance. Same with the 270, you could be talking about the 270 Wby mag???
I feel too many worry about what cal to use for hunting instead of worrying about what "bullet" to use in what ever cal they pick for the size animial they are hunting!!
A 270, 150 grain Nosler partition (or heavier) works pretty good on moose on "side shots", as does 180 grain NP's in a .308!!
Personally, i'd pick a 30-06 over either the 308 Win, or 270 Win..
Drilling Man