Friends. Focus on impact energy not a specific caliber or cartridge. Any cartridge delivering 2000 ftlbs on target will kill elk. More is better to the extent you can hit what you are aiming at. Muzzle brakes are godsends. Make sure your bullets are designed for your probable ranges. Most of the premium bullets out there have minimum impact velocity of 2000fps. Paper is easy to kill at 1000 yds but do you have an expanding bullet with 2000ftlbs?