I would recomend a magnum for sure, wether it be a 7mm up to a 338, my choice is the trusty old 300win mag. The non mags will do alright but have alot more drop at distances, I wouldnt recomend an ultra mag either, most who have purchased them either trade them in orend up downloading because of the recoil!. You need to stick to something that wont make you flinch when you shoot, makeing long distance shots requires constant practice at ranges to become sufficient and build confidence in your abillity. If you dont reload already I would highly recomend getting into it, you will need to produce ammo taylored to your rifle. You will also need to do some upgrades to the rifle you purchace, trigger, bedding, free-float if its a wood stock, re-crown the barrel " target crown works best", and high quality scope, rings and baces. Is all of this nessesary, well no if your lucky!, yes if you want to hunt ethicaly.