It is not the firearm, but bullet placement which matters. Shoot what you are comfortable shooting, and most accurate with. Some popular modern firearms including the 6.5 Creedmoor, etc. are considered to be too small for dangerous game and elk. Minimum caliber requirement .270 win w/ 150 gr. Bullet. Personally we prefer a .30 caliber slug. The bottom line is if the shot is placed properly, the animal will go down.