22 rimfire....small game, plinking, target
243 Winchester (only because 6MM Remington ammo isn't always easy to find. Especially in lighter bullets)....Varmint to deer
7MM Remington Magnum....Deer to Elk, Moose, Bear. Ammo very common.
375 H&H....For anything the 7MM Remington Magnum wouldn't do....Ammo available world wide.