Originally Posted by Mystro
If you need to shoot through barriers with the 9mm, Hornadys critical duty in 135jhp is just what you want. They also performed very well without shooting through barriers. There is quite a few reviews of them on YouTube with excellent results in ballistic gel. I like deeper penetration so they are just what I like in my 9mm guns. They also can make the 9mm a respectable woods gun if need be.
Carjacking, for one example.
The Feds didn't overwhelmingly choose .40 due to enhanced barrier penetration based on one anecdotal incident, they researched it like crazy. After all that major research, practically all federal agencies still use .40 S&W or .357 Sig over 9mm