Hey there,
I have killed animals from elk at 587 yds, and muleys at 600 plus for the past 5yrs with my tikka T3Lite 300 WM. I have found a great factory round that gets the job done (Hornady Superformance 180grn) every animal I shoot goes down no problem with one shot great penetration, expansion, and knock down power in that load. I will say this, understanding long range and your rifle is 90% of the battle
I had a custom Muzzle Break put on it (due to the gun being so light and I wanted recoil reduction for accuracy) plus I reduced my trigger to just above 2 lbs. The gun literally kicks no harder than a 243 and I have a lot of fun carrying her around shooting varmits out past 700-800 yds! This year I am stepping it up and going for a bit better scope to see what she does out to 1000 plus. My scope needs an upgrade but I am truly confident in this rifle and that bullet as it has never let me down.