To add to what natman said, an increase in diameter does not increase the volumn in a linear pattern. So the weight/length ratio changes as the diameter increases. As bullets get larger in diameter, the length of bullet to gain, say, 10gr., actually decreases. EX: hypothectically let's say a 7mm(.284") bullet takes a length increase of .005". A .458" bullet may only take .001" to increase 10gr. in weight. But the change is not linear. You can't say it takes "X" increase in length per "Y" change in diameter. Hope that makes sense. Circles don't work like squares, basically.
David
