FWIW, I recall an article in one of my hunting rags a few years ago in which a autopsical study was done in coordination with a bison cull out West somewhere - private ground as I recall. The animals culled were all shot in the chest with rifles, and details were recorded as to which animal got shot with what, how, angle, distance, entrance, exit (if any), animal's reaction, etc., etc. Then autopsies were performed on the animals. One thing that stuck with me from that article was that they determined that most of the animals that dropped at the shot (obviously not all did) had broken blood vessels in the brain even though shot in the chest. IIRC, theory was along the lines that the bullets possibly impacted in the DRT animals at just the right time just after the animal inhaled and blood pressure and tension in the body was at it's highest, and assisted in the "shock" busting vessels all the way to the brain and shutting their CNS down right now. Their study, not mine. A quick search did not turn the article up for me just now. And I'm not even sure which mag it was in, but the American Hunter sticks in my mind.