Hello! I have a Remington 700 bolter with the heavy 28" barrel, full muzzle-brake and recoil-pad chambered for .300WM(I load straight from the chamber, never from the mag.) I am quite happy with the stock performance of the rifle, but wish very much to increase the range and power dramatically. I am an avid shooter/hunter, and take great pains to practice religiously with my rifle. My mindset is "one shot, one kill" thanks to 12 years in the Corps, and I will give up lots of meat to ensure the animal goes down fast with minimal suffering(I know that usually the best way to do this business is get up-close and personal, but most of the really nice elk I've come across lately have been too smart for me, and I've had to pass up some shots due to the ranges involved.) Please advise which rounds(wildcats or otherwise)ya'll recommend for long-range(+400yards)elk hunting that would be a good mod for my Remington 700 heavy-barrel rifle. I don't care if it means short barrel life so long as the cartridge is a heavy-hitter and a straight flier. All I've looked at is so far is the .30-378 Weatherby, the .30 Cody Express and others in that category.....THANKS!