Best elk cartridge in the world is the one you have in your hands when you find a good bull. If everyone spent as much time learning what is needed to get that done as they do worrying about what round to use, there would be a lot more bulls killed. Pretty much anything within reason will work if you do your part. I'd rather hear from some of the guys that kill big bulls every year regarding methods, than listen to a bunch of guys postulate about what I should shoot it with.