Velocity is really the key to instant death. It is the hydraulic action in the brain that causes instant shock. Back in the day, I have taken gangsters to the hospital who were shot with .22 zip guns and the bullet just stayed under the skin. (they did have a hell of a headache though)It warms my heart to see a chicken killing varmint dealt with.
I like the CCI Quiet but I mean the segmented. I wonder if that is key for performance.