The most important part is picking the right opponent.
So, interview your bad guys, and make sure they are small enough so hollow points penetrate enough to get to their vitals.
Also, make sure they agree not to wear vests, or heavy clothing that might make the
HP's penetrate less. Have them sign the agreement that anything that might inhibit penetration, wallet, cell phone, medallions, note books, holsters etc. are to be taken off prior to their attacking you.
I'd also like to see a prison study of the average size of your robbery and violent crime
convicted felon. Somehow, considering the percentages, size, and that we let them lift and get bigger in prison, I'm not all warm and fuzzy with shallow penetration HP's.