Upto a 1000 yards, I can keep up with the .338's et al with the humble 6 NBR. Beyond that one needs the bullet to remain supersonic, and unfortunately the only calibers that seem to cut it are the .338, .50 BMG, .416 Cheytac etc.
The ergonomics of the rifle are critical in this type of shooting, and one typically can get an off the shelf rifle or build one. Savage has a .338 LPM but I would hesitate to shoot one without a muzzle brake. I have tried it when I had my TRG, and it is no fun. With a can or a brake the recoil is emminantly manageable.
Also keep in mind that if you are hunting with this caliber, you are hunting the most dangerous game of all.. Man.
