I've been thinking...given the higher sectional density of a 380 grain .375 as compared to a 500 grain .458, wouldn't the .375 penetrate better with a similar muzzle velocity?
I think the advantage in sectional density is 13% in favor of the .375, while the .458 has a 32% advantage in weight. I understand that the increased weight would equate to more momentum but wouldn't that be offset by the relatively smaller frontal profile and resulting decreased resistance of the .375?
Just a thought.