I am a big fan of the Winchester XP3 FailSafe.

They shoot great out of my .270 (your mileage may very), and have always put the animal on the ground. Some were passthrough, some were not.

Regardless of what ammo you pick, in a .270 Win, I would want a bullet on the heavier side for elk, something in the range of 140 - 150 gr. Not quite as flat shooting as a 130 gr, but with a .270 and elk, you will probably not want to take those really long range shots anyway.