The lot of BH 77tmk ammo I have gives me 2758 fps in a 20" bbl. At 6000' DA I'm at 1800 fps @ 580 yards and at 4000' DA I'm @ 550 yards. So basically, anywhere I've hunted for elk the BH 77tmk load would be sufficient. Is it perfect for all skill levels? Safe to say, no.
In that same sentiment, is a 7mm or 308 caliber magnum the best choice? Not in my opinion. Lots of standard bolt face short and long action cartridges shine at sub 600 yard shots. With less recoil and cheaper ammo those cartridges allow for more real world practicing (which most will never do anyways) and hopefully a better marksman.
If you can't be accurate at 600 yards with a 243, 7mm-08, or a 308 then the magnum version in those calibers aren't going to fix anything for you. In fact, they will make you an even worse marksman.
Jay