That same question has often been asked but it is easily answered by looking at some of the ammo results from shooting newer shorter barreled semi-autos and seeing that yes, shorter barrel lose velocity. Do you really get that much more from a short barreled 9mm than from a 380 - probably not. You get some increase with the 9mm but I have often wondered if it was worth it all to go to such a short barrel.
It is also said that if you carry a smaller caliber handgun you should practice a defensive technique with it to assure your survivability. Most folk think that the 45 or the 357 mag may be 'one-shot fight stoppers' but those aren't the folk who may have missed with the first two shots, finally connected with a non-fatal 3rd shot and possibly ended the confrontation with either a fatal or debilitating 4th round. I would rather put my $ on my continued practice with a smaller caliber for defense than no or a lack of practice with a larger caliber with a bullet design of current vogue that is supposed to work marvels.
There is nothing wrong with the 9mm - you just have to practice with it. I practice a double tap - that is how I was taught to use a 9mm. I use the same technique with smaller calibers except that I add to that effort with one more round - either a triple tap, so to speak or a double with a finisher.
Lots of folk poo-poo the smaller calibers and often reports of shootings indicate smaller calibers failed to stop the attack, robbery, etc. However, if you review the reports of those who trained to use handguns and who practiced with smaller caliber handguns you may be heartened to read that it required only one shot or possibly two to end the fray. JMTCW. Mikey.
