There is a big difference between bullets suitable for deer and those that work well for elk. It looks like the OP is searching for a bullet that kills elk quickly, like the deer he has been shooting. Prepare for disappointment!
I have personally killed about 15 elk in recent years, and have been present when another 50 or so were taken. Do not expect an elk to drop where it stands, regardless of caliber, bullet type or construction, unless the elk is hit in the spine or BOTH shoulders are broken. Exceptions do occur, but it is far less likely to get a "bang - flop" or "dead right there" with elk than any other critter that I have hunted. Deer seem to be susceptible to shock, elk are almost immune to it. So choosing a bullet that fragments on impact with maximum energy transfer just doesn't work for elk as well as it does on deer. The most reliable results on elk are controlled expansion designs that are heavy for caliber or mid weight monometal bullets. Bergers, Ballistic tips, etc will kill elk very well if slipped into the chest through the ribs, but problems develop far too often if the heavy bones get in the way.
A pet peeve of mine is those who constantly preach accuracy accuracy accuracy... so a little rant: how a bullet performs IN game as large as elk and moose is FAR more important than a half minute of angle difference in accuracy! Anybody disputing this is spending way too much time on a computer and the range and not enough time in the bush.