Without wishing to introduce a dog into this argument, I think that bullet weight has more relevance than just the 15 grains difference in weight. Along with that weight difference I think you find perhaps a little different bullet construction, since the bullet makers assume that the heavier bullets are going to be used on progressively bigger game and perhaps make the jackets a little thicker to slow expansion and hold together. I would suggest that it's more this difference in construction than the mere difference in 15 grains of weight that perhaps makes the heavier bullets a somewhat better choice for larger game. That being said, not all bullets are equal, so some bullets may be functional on bigger game at lighter weights. I would not necessarily construe this to hold true for all bullets in a lighter weight class.
