well john this was my second bowhunting season. I went after elk and arrowed one my second evening out. The young bull maybe went 40 yards from where he was hit. The broad head completely destroyed the right atrium so whatever blood that was returning to the heart was lost. As a result that elk died just as fast if not faster than it would have with a bullet. Ya shot placement is the main thing if u get heart or double lungs they animal will be down before you know it.