I have always been leery of a bullet that needs to do a trick in order to be effective. Most people are familiar with Murphy's law, and knowing self defense, if something can go wrong, there is a high likelihood that it will. My personal preference is for a bullet that will be effective even if the trick that bullet is supposed to do fails to materialize.
Ammunition that has been proven effective in both testing in a lab, and in actual use on the street gives me the most confidence in it's ability to be helpful when it is needed. Hence, I review manufacturer's testing, FBI testing results, any one shot stop results, and any other data on ammo I can find.
So far, my "go to" ammo for 9mm is 124 grain +P+ hydra shock, and Federal's 230 grain hydra shock for 45 acp.
Both types of ammo are used by many LE agencies, and neither one is so unusual as to cause excessive problems in court if they were ever used.
