Unfortunately, we can't predict exactly what a bullet is going to hit when it strikes the deer. Hitting a rib on impact will obviously expand the bullet faster than hitting "rib meat". This phenomenon causes me to lean towards a bullet like the nosler partition. I usually hunt from a tree and getting a pass through with a low exit will normally create a good blood trail. The theory is no different than for an arrow. The lack of blood trail that can occur is sometimes due to the shot hitting high in the deer's chest. The blood simply fills the chest cavity but never high enough to come out of either the entrance or exit holes. The shortest tracking and least meat damage seems to come form a shoulder blade hit. That hit typically sends the bullet and parts of the shoulder balde through the vitals so even if the shock to the spine only stuns the deer the organ damage finishes the deal. The deer tends to just tip over as if the wind blew it down.[:-]