22, 6 or 6.5 Creed will do it and be much easier to shoot well than 308 or 338 fed. 140 eldm from my 16.5 inch 6.5 stays above 1800 fps to a bit over 700 yards. Vast majority of my shots will be well inside that so I'm golden. My daughter dropped a nice muley at 475 with it and son got his first at 350. No drama. Dead animals with good sized wound channels thru the dreaded shoulders. An ultra light rifle with no suppression or brake needs to have recoil minimized to aid placing the bullet where it needs to go in weird field positions. And have a stock that actually aids in the shooting process, not necessarily at light as humanly possible but that's just my opinion after shooting some ultralights that just didn't manage recoil well at all.