All you need to do to see the difference in killing power of the 5.7 FN w/ non expanding ammo vs. the 9mm w/ hardball is to shoot a few 2.5 gallon jugs of water. Even the .45 ACP's hardball won't do much in the way of lateral damage to the jugs. They hardly split the sides of the jug at all. The 5.7's non expanding 27 gr. HP will rupture the sides of the jug to about half way back in a much more convincing manner. They, the 5.7 bullets don't penetrate nearly as much. The back of the jug, that's 12 inches, is all they have.
The Ft. Hood shooter used a 5.7 and kill many of his victims. Rep Giffords was shot through the head with a 9mm rd. Her doctor said that over 30% of such people so shot survive do to due to lack of laterial disruption. I can assure you that a 9mm HP load would rupture the head and blow out the back of it. Never heard of anyone surviving that kind of damage. E
