creditman: most of my experience has been with mature bucks. They were high shoulder shots, due to the circumstances, I needed them to drop in place and not run (it worked). One small doe was shot thru the lungs behind the shoulder. She stumbled a few yards and went down. Exit hole was about quarter sized, and lungs were mush.
IIRC, Mule Deer (John Barsness) has said that the AB was designed to mimic the Partition, i.e., frangible up front and good penetration from the remaining base. That has been consistent with my experience to date
