Full Metal Jacket (FMJ) or Jacketed Hollow Points (JHP) ammunition ?
Both have their uses
I fired .45 cal Corbon Power Points into water filled paper milk cartons. The bullet stopped in the 4th carton and had expanded to approximately .70 cal. Lots of stopping power. I was too close and got a bath. Ha.
Ever seen this site
Unless you are expecting to be facing an armored opponent JHP is the way to go. The wounding ballistics of any expanding or fragmenting ammo are more effective than the deep penetration and tumble of FMJ.
I just want to kill the person I'm shooting at; not everyone in line behind him.
Each has it's place
I use Hornady Critical Defense ammo in my carry weapon ...