Hunting similar situations here on gas line ROWs, I've found the 257 Wby hard to beat. It's not quite as flat as some big boomers, but it has less recoil and less muzzle blast. I tried some big boomers and kept coming back to the 257. To be able to point and shoot to 400 is golden during the rut where you barely have time to shoulder the rifle before they are gone.
