Neither of those rounds are "Elk" rounds. If I were going to use the 6.8 on Elk I'd want the strongest bullet I could get such as the 110 gr. Nosler Accubond or even better the 110 gr Barns TSX or TTSX. These bullets will hold together when smashing through tough elk bones. You want a bullet that will peneratrate THROUGH the animal and let out LOTS of blood and in LOTS of air!! I'd also limit my shot to a broadside shot at < 150 yds. Elk are BIG and hard to bring down if not hit in the right place.