9mm has undoubtedly recently been experiencing a resurgence in popularity with law enforcement and civilians alike. At the same time testosterone levels have been dropping amongst western men. Coincidence??
The only .40 I own is a drop in conversion barrel for my Glock 20. It's a pussycat to shoot and has served well on all kinds of critters. For me the minimum requirement I have for a serious handgun is what I'd feel comfortable with crawling on hands and knees through thick Texas brush in the dark after potentially wounded and pissed off hogs. I've done it with the .40 and it's gotten the job done. I wouldn't trust a 9mm for that unless it was loaded with boutique, heavy +P hardcast. Even then I would hesitate.
I prefer the 10mm but the .40 is right there nipping at it's heals performance wise. I've killed enough animals to know that there's not enough difference to make a difference between .40 and garden variety 10mm defensive loads. It's also nice to know that in a pinch I can use .40 ammo in a factory 10mm if I needed too.
