Not all cartridges do all things. where we live, where we hunt, and, tradition is going to dictate what calibers we use, and that's not including who we are, big burly men, wifes, children even grandpa's like my self will use cartridges suitable for each of us. I've killed far more elk with a 270 win than all my other cartridges combined, my wife shoots a 270 win for elk, my son shoots a 270 win for elk, my daughter shoots a 30-06 for elk, but to be sure all in my family have killed elk with many different calibers that we own, including a 6.5 Creedmoor and even the 6.5x55 Swede that's basically a much older by a hundred years ballistic twin the Europeans have been killing Moose with since the late 1800's. In fact I going to re-barrel my old 1905, 6.5 x 55 Swedish Mauser back to a 6.5x55 Swede. The main thing with any caliber / bullet combo is knowing it's limitations including the shooters limitations and how the gun is set-up. My cousin for years used a 280 Remington on elk great cartridge before he passed away. You want to shoot long range on elk as an example and we do, and we use bigger cartridges with a bullet that carries well at distance and have extra eyes out there to help you out. Want to hunt elk in dark timber close range I can tell you a 30-30 or 300 savage will get the job done and in some ways better than over powered over scoped magnums. I don't put a lot of stock in pure numbers like foot pounds of energy that only gives part of the story and maybe a base line if some one were interested in these types of things. 45-70 at close range will knock the dog snot out of any elk at closer ranges. Interesting sometimes to talk about, and always good to get different opinions.