I see where you are coming from eddie, and i agree with you. obsidian is sharper than steel, that is true, but that is a one moleculat edge piece that is used, surgical scalpels are not knapped. in other words no one is taking a ragged obsidian arrow points and cutting open a heart with it, its just used in a different manor. as you know being a good knapper, when you make an arrow head, even if its very very thin, the cutting surface has a lot more surface area that a steel cutting surface, and the more surface area the the mor drag and the less efficient the cut is. just like we stated how if i take a flake of obsidian it would slice deep into my arm with little effort, but a knapped obs point may cut a bit but it wont slice as deep and clean and easily like a flake will.
i think we all agree that if you hit the lungs or heart or arteries, the animal will die, no question about it, but a lot of times the stone pushed those organs out of the way instead of doing the maximum damage that a fine razors edge will. a field point to the heart will kil a deer, but if you liver shoot a deer with a field point there is a great chance you will lose it but if you liver shoot with a broadhead, the hemmorage is too great and you most likely will find it within 100 yards.
so i think what is being stated is, steel is more efficient and more forgiving. its less likely to break and will penetrate more without any question and will have a greater chance of recovering on a not so perfect shot.
and yes i have shot dead deer with stone to get examples as well as live deer, and yes a stone point will destroy a rib bone, but if you hit a rib bone going in, you lose a lot of energy with a stone point that you wouldnt lose with a steel point. that has been proven over and over, me and ryano both have had enough experience in shooting stone to know that getting out both sides of deer is tough to do with stone points, but easy to do with steel.
so its not in question does stone work, we all know it does, but what is being discussed more than anything is are you at a handicap with shooting stone.