FWIW:
I never shot an Elk with a 270, but one heck of a lot of 'em fall to it every year here in Oregon. I think that the 270 WSM with 150 grain premium bullets shoould be just fine if the shooter does his part.
That being said, 270 Win is the lightest I would go for Elk if you are not a local. The locals can decide to pass on a tough shot and come back tomorrow. Out of towers may want the capacity to take a quartering away shot at 250 yards. The 270 WSM gives you a little more ooomph and is probably going to penetrate well under such circumstances.
Just my 2 cents . . . .
BMT
