Here is my feeling on that point. Many heads, especially some of the chisel tip heads seem to leave very large entrance wounds, larger than there actual diameter. This tells me that before going into the hide it is pushing it in and then cutting, then passing through the vitals (hopefully) and then out the other side. If this is the case, that is the head I want to shoot. You are passing completely through the animal, but getting increased tissue damage at the point of impact, maximum tissue damage to the major organs, and a liberal exit wound. This means, a lot of damage, a quick kill, and an easy to follow blood trail. As long as you are passing through, I'll take the big nasty entrance over the smaller cleanly cut entrance.