my wife killed her 6x7 montana bull this past fall @515 yards with a 6.5 creed and the 143 eld x the bull went 30 yards and fell over dead soYUP,.. ^^^ I've studied them SERIOUSLY, too for, my 6.5 Creed, Deer / Cow & Spike, Elk "Up Close", 500 Yds Max., Hunting bullet !
I settled on, the 143 ELD-X's for, THAT, use.
For big Bull's in most any of, the 7MM's, Try, the 168 to 184 grain, H-VLD'S or, Elite Hunters, as Berger's, Kill,.. WELL !
Or, like Bigngreen said,.. the 195's if you don't mind, the extra, Recoil !
the 143 will and does work for big bulls not just cows and spikes elk are not bullet proof