Hatcher's theory is big and slower is it not? But shot placement is a major factor. After all Bell shot elephant with a 6.5mmX54 Mannlicher. But apart from anything else larger calibres making a larger primary wound channel tend to provide a larger blood trail to follow in the unfortunate event that an animal is not dropped cleanly. But if you are a meat hunter and can place your shots a slower more modest and smaller projectile is surely preferable as it does far less meat damage?