I agree with what the others above have said and I think that tougher construction will generally trump SD in penetration, SD being nothing more than numbers anyway......but I think this bullet length thing might still have a place in the scheme of things.
Specifically I notice in reading the reports of those using them that the penetration of some of these very long, high BC bullets like the 180 gr 7mm Bergers seem to penetrate fairly well, and especially at the longer distances after things have slowed down a bit. My thoughts on this are not based on any personal experience because I do not use those bullets for any hunting, but rather on the reports we see from knowledgeable shooters who are using them on game.
I had trouble understanding how a thinly constructed bullet could do a decent job of penetration on larger animals but it seems that they simply are so long and heavy for caliber that they just have more weight and length to lose after impact, but enough left over to penetrate as much as they need to.....this is the only notion I can come up with that makes any sense to me as to how and why a thinly constructed bullet can get through game meat.....but I don't think it's a numbers thing...just sheer weight and length(heavy and long for caliber).I think it might also help that impact velocities are down quite a bit because the bullets are used at long range.....but what do know?
Still, I would not depend on SD numbers to tell the story, and I think that if a guy is going to use a thinly constructed bullet on anything bigger than a deer, he may be better off going to something heavy for caliber.
