9mm is fine. Or bigger.
This article shows the importance of caliber choice. Fortunately for the victim, the perp used the wrong caliber.
Police depts over the country have abandoned the 9mm in favor of the .40. Each person has their own opinion of favorite calibers but the caliber choice can be critical to bullet placement as well as shock value.
9mm is fine. Or bigger.
While looking at energy specifically there is little difference between 9mm and .45 acp. To achieve "HYDROSTATIC SHOCK" you need to impose enough energy to cause a spike in blood pressure which should cause at least a temporary loss of consciousness. Both the 9mm and .45 acp have a very hard time achieving 500 ft-lbs of energy at the mussel. This is one of the main reasons I decided to switch from carrying a 9mm to .357 sig.
This taken from Wikipedia
Ammunition selection for self-defense, military, and law enforcement
In self-defense, military, and law enforcement communities, opinions vary regarding the importance of remote wounding effects in ammunition design and selection. In his book on hostage rescuers, Leroy Thompson discusses the importance of hydrostatic shock in choosing a specific design of .357 Magnum and 9x19mm Parabellum bullets. In “Armed and Female,” Paxton Quigley explains that hydrostatic shock is the real source of “stopping power.” Jim Carmichael, who served as shooting editor for Outdoor life magazine for 25 years, also believes that hydrostatic shock is important to “a more immediate disabling effect” and is a key difference in the performance of .38 Special and .357 Magnum hollow point bullets. In “The search for an effective police handgun,” Allen Bristow describes that police departments recognize the importance of hydrostatic shock when choosing ammunition. A research group at West Point suggests handgun loads with at least 500 ft-lbs of energy and 12 inches of penetration and recommends:
One should not be overly impressed by the propensity for shallow penetrating loads to produce larger pressure waves. Selection criteria should first determine the required penetration depth for the given risk assessment and application, and only use pressure wave magnitude as a selection criterion for loads meeting minimum penetration requirements. Reliable expansion, penetration, feeding, and functioning are all important aspects of load testing and selection. We do not advocate abandoning long-held aspects of the load testing and selection process, but it seems prudent to consider the pressure wave magnitude along with other factors.
380 would be the smallest I would carry for self-protection. In a pinch, though, something is better than nothing. I prefer to carry a 9MM or 40 S&W
i think anyone with a CCP should have a .380 in their pocket
have you noticed how many manufacturers are now making .380's?
keltec was making 52,000 a year - that is 1,000 every week so first Ruger competed in 2009 and by now many manufacturers are making them - rumor is S&W might be coming out in an M&P 380
i like the new sig sauer in 380- looks like the colt mustang
for main carry piece - 9mm and up - the choice is wide open - 9mm is obviously the most popular and the cheapest round
...I have relied on a .22 revolver with short HP in it...if my choice had to be .22 now, I'd use stingers...my favorite defense caliber is .45ACP...anything in between would work if it had to...if I do my part...my LEAST favorite in that spread would be .25ACP....
While I'd like to carry no less than a 9 mm - I switched to .380 (9mm short) about 2 years ago.
I carry my Ruger LCP in a DeSantis Nemesis Holster in my front pocket more and more.
If it's cold (coat) I'll still carry my .45 or 9 mm, but no where near as often as I used to.
I'm getting lazy
I grudgingly settle for the LCP way too often, but I have tried to compensate by adding the CT laser. On this little pistol, that virtually disappears in my largish hands, it makes a huge difference in my ability to put rounds on target, quickly. Every little bit helps, when you are under-gunned.
I put that exact same sight on my Glock 26 - I wish I had put it on my LCP