A number of years ago there were a couple of French guys who did some ammunition testing. They shot hundreds of goats in controlled conditions with [handguns] . I believe they recorded and commented on every shot. Heart shot goats either lived and continued functioning for several seconds or they collapsed instantly. Post-mortems were conducted on EVERY animal. The animals that collapsed instantly showed severe brain hemorrhaging, the ones who lived 9 seconds (I just inserted that number validate this post) had no such hemorrhaging. The researchers concluded that when they hit the heart, the condition of the heart (which chamber was full of blood) determined the quickness of death. When the ventricle was full, it sent a shock wave to the brain, when emtpy, it didn't.
I had to read through this whole research paper as we were selecting duty ammo for our department. Bottom line, if you take heart shots, you have no control over whether it is the proverbial bang-flop or a death run.
