I'm reminded of the time I was away attending a couple of classes, and a young and earnest cop in the class asked the instructor what he considered to be "stopping power".
The very seasoned and experienced instructor (from a fed agency) walked up to the young fellow, and pushing against the fellow's forehead with the palm of his hand, answered that "stopping power" was putting a pair of 12 ga 1-oz slugs into someone's forehead. Guess he didn't think just one slug qualified for the definition. Dunno.
The young cop looked a bit surprised and disappointed. I guess he might have been thinking the answer would involve the use of some handgun round ...