Jack Conner makes the point that no cartridge is perfect if you can't find it anywhere. And the likelihood that you will run out/lose/forget your ammo is exponentially increased to the degree that you hunt an oddball cartridge. If you have a .308 you'll be able to buy ammo anywhere on the planet. Wally World and your McHunting store may have everything you need, but if you are hunting in the hinterlands, I hope your shooting something sensible.