Originally Posted by DigitalDan
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With cup and core bullets, of equal construction, the higher SD bullet may not kill any better, but they will absolutely penetrate deeper (270/150 vs 308/150).


If all else is equal, perhaps. SD is a metric oft relied on to riddle expected results, but there are so many other factors at play that it is a guess on the best of days. It is nothing more than a ratio of weight/diameter that will begin to change as soon as the target is met. What is the SD when 30% of weight is lost? What is it when the bullet begins to tumble. The world of terminal ballistics is one of the last remaining scientific black holes in shooting sports and I suggest one not spend a lot of time theorizing about what happens and the results thereof. Just put the bullet where it needs to go.


There's a pretty well established relationship between SD and penetration in conventional bullets. Nice thing about penetration is fairly empirical results can be arrived at even by a layman. So in the case of the 270/308/150, it's really not a "black hole" at all. And I promise a 150 Partition from a 270 will out-penetrate a 150 Partition from a 308. So what's better, putting a "bullet where it needs to go" that penetrates more or less? Generally the difference matters little, but occasionally on bigger, big game it might.



“Perfection is Achieved Not When There Is Nothing More to Add, But When There Is Nothing Left to Take Away” Antoine de Saint-Exupery