The 9mm gets its energy from speed.
Over and over again, I keep reading that the experts are recommending light (115g) hot loads in 9mm for defense.

The biggest issue with the 9mm 'not cutting it' is overpenetration and small wound channels due to failure of expansion. When a hollowpoint encounters heavy clothing, or other barriers before entering a body, the HP can plug up and fail to open. It will then perform like the mililtary FMJs and zip right through without tearing too much up. Not what you want for defense. Go light and hot, andyou maximize its performance. There is also one HP out there that pushes flat instead of relying on hydrostatic pressuse inside the HP toinitiate the expasion process.

I like 40 and 45, but the 9's sure are getting small and comfy to carry.