Actually, Mike, if done correctly, Bark kicked up by the ball/bullet passing through the limb under the squirrels head slams into the jaw of the squirrel, and either breaks the neck, or kills by the concussion blow delivered to the central nervous system. A barked squirrel will show no wound. If there is any bleeding, it will be from the mouth, from broken blood vessels in its sinuses, and throat. :hmm:
I have never barked a squirrel, but I have seen squirrels that were barked by others.
I use to practice making this kind of shot, by shooting UNDER the bottom of beer and pop cans with my rifles. You had to learn to hit the right amount Under the can for a chunk of dirt to kick up and throw the can into the air, particularly when using a small caliber rifle like the .22. It is VERY GOOD PRACTICE for making this kind of shot on game. "Kicking the Can" with high powered rifles at 50 yds. is a lot of fun, too. We once did this at my BP club using our larger bore(.45+) MLers.