i have only been hunting elk for about 5 years, but my dad has been hunting them for 25 years. if you are only shooting elk at 300 or less both of these round or almost any round on the market that will shoot a decent group and weighs at least 150 grains will do. I have been using Noslers ballistic silver tips though and my gun likes them and the elk hate em.
me or people i have been with have shot 5 elk in the last 2 years and they have all been with the ballistic silver tips 150gr from a hundred out to 300 yards and they have all been one shot to drop them and one shot from a couple yards away to finish them off.
the most important thing to remember when hunting elk is good shot placement. where i hunt i can have them run very far (to many hunters willing to tag my animals) so i use a high shoulder shot so i break the spine. this is a shot that will work with almost any thing you hit them with. Either i hit the animal and it's dead or i miss. and for those best of the west guys no that isn't where i heard this first my dad has used this idea for years and has been able to kill many elk in his days of hunting.
If i had to pick between the two bullets you are talking about i would take the one that is more accurate and the max range you expect to shoot. that is what matters the most as long as you have a bullet that will carry enough energy (you don't have a problem there