Folks, this has been interesting reading and I'm sure I can't add anything that has not already been said. However, I have hunted Elk for more than fifty years, using several calibers, and have to agree with the folks who believe in accuracy / bullet placement rather than energy on paper.
I have killed Elk with the .270, and about everything between up to the .338 and 35 Whelen. If there was ever any difference in "killing power", assuming like shots, between any of them I was never astute enough to see that difference.
On one particular hunt, back around 1985, I ran into a old gentleman on the North Fork of the Clearwater in Idaho who had a very nice 5x6 hanging. After introductions and a cup of joe the conversation turned to guns. He showed me his "Elk Rifle", it was a 25-06, and he was proud as a Peacock. I asked him how many Elk he taken with this gun and he replied, " I reckon I got 11, or maybe 12, out of that first box of shells...then the darn kids got into em' and shot em' up".
Everytime I hear this discussion on what makes a Elk rifle I think of this story. Is there anything magic about the 25-06? I doubt it. I own one and although it is a fine little rifle, it would be my last choice for an Elk rifle. The .270 is not my first choice either. Although I have killed more Elk with a 7x57 than any other caliber, it would not be my first choice. My .338 has only taken two Elk, and I didn't see any magic there.
The .300's were OK, but they lacked that certain magic also. My 30-06 comes to mind as posessing something that borders on magic due to its "shootability" with a heavier bullet, but if I were to choose it that would leave my 35 Whelen completely out in the cold, and I don't want to do that.
So, Is the .270 WSM a good Elk cartridge? Yep, I would say it just might work about as well as anthing else, but I do believe...it would not be anything magic. These are just my thoughts.
Respectfully, Russ