Off the top of my head, I have killed elk with:

6mm Rem-100 grain Speer BTSP
.25-06 Rem-110 Accubond
6.5x284 NORMA-140 AMAX and 140 hunting berger
.270 Win-130 grain winchester factory loads and 150 grain speer hot cor.

As much as I dearly love my .340 WBY, I can't really say that any of the elk I have taken with standard sub-.30 rounds reacted any differently than they did when I used my .300 H&H, .340 Wby and .375 H&H, which I have killed elk with too. Bullets make much more difference than what round throws the bullet out there...but there's no reason to beat that dead horse.