My thinking is that the bullet choice is more important that the caliber choice. A .243 with a premium stout bullet that will penetrate thoroughly (i.e. All Copper, Swift A Frame, etc.) is a better choice than a .300 mag with a soft bullet that will disintegrate before it gets through the vitals. I have always appreciated a bullet that will go completely through an animal and hold together. The whole caliber argument can go on forever as everyone on this site knows, and while it is fun, it can drive a person nuts. Shoot straight with what you know and stay within your limits. That's all I have to say about that.