My younger brother has hunted almost exclusively with a .308 all over the west, east, north, south, ect.......
He has taken down 3 elk with 4 shots with his .308. Never recovered a bullet.
How dead is dead???
The only advantage to a "magnum" is that it extends your "useful" range 50-75yds.
When ever I go back to hunt "out west", I'll be taking my Rem. mod7 in 7mm-08 in spite of owning a .257wbymag and a .300RUM. My best friend took it in Oct.'05 to Colorado and took a 6x6 elk that weighed a "measured" 1,200lbs (has a picture of it hanging from the scales- I didn't believe it either!!!). Only one of 4 rounds he put into it was recovered -not the Nosler 140gr Part. I sent with him to hunt with, but a Sierra 140gr FB that was for "checking zero"- it lodged under the hide on the far side- not a failure!!!). (Kept shooting at guides insistance- all four shots individually would have taken the elk.)
Later in camp, all the guides and half the hunters tried to "buy" the gun from him. Two borrowed the gun for the rest of the hunt. (11lbs vs. 7lbs makes a difference at 10,000' and walking 10-12mi per day !!!!).
Use a Nosler 150gr Partition over either RL-15, Varget, or H4895- whichever your gun prefers and use the .308 with confidence. A 165gr if you "insist"; my brother dosen't like them because they don't shoot as well from his rifle and aren't as flat shooting to 300yds.
(P.S.) "whayyyyyyyy back when" There was an episode of the old "American Sportsmen" TV show that had Fess Parker (played Daniel Boone on TV series) hunting with Fred Bear (Bear Archery) and Curt Gowdy(sp?) for Grizzley in Alaska. Fred took one arrow to put down a nice grizzley. Fess Parker took two shots with 180gr Winchester Silvertip .308 to bag his.
The .308 will do the job if you do yours.