I've taken numerous whitetail and mule deer with 140 grain AB's and a couple with 140 grain XP3's. Both are very accurate in my rifle, much more so than the 130 grain TSX, which is the only 130 grain bullet I have shot through it. The .270 WSM has plenty of pop to shoot the 140's, don't worry about that, but in the end, I'd just shoot the most accurate bullet, whether it be 130 or 140 grain.