I have seen a lot of dead elk and the largest dead I have ever seen was killed by a 7mm-08 at about 100 yards in the timber (by a first time hunter who was "a little lost" at the time). The antlers were amazing and the bull's body was huge. One shot from his 7mm-08 with a 160 grain Partition dropped the bull in his tracks.
My favorite .270 bullet for bull elk is the Nosler Partition 150 grain. It works.