Doc: Great story! Hard to believe you can hit them that well and they manage to keep it together.
Indeed, Bob!
Here's a pic of the heart of my buff taken immediately upon removing it from the chest. The wound you see here was entirely due to the bullet (300 gr Swift A-Frame), the skinner's 8-inch knife is merely shown for scale.
This bullet shattered the near shoulder blade (scapula), passed through the chest cavity and into the far shoulder, where it was found under the hide. This is about as well as you can hit an animal in the chest, and he still lived 6-8 minutes. Plenty of time for a "dead" buffalo to do a tapdance on your head if he takes a notion to do so.