That is not to say .40 is not a great choice. I just find the notion that if you are not big and strong enough to carry a .40 then a 9 mm will do a little silly.
I find it silly as well but so far you're the only one who has said that. Which may be ironic.
Wiggling gell and Cooper notwithstanding, all the data I have seen and read tells me that 9 mm is an effective round, with virtually no difference in performance than any other service caliber in stopping bad guys.
You may have mis-read, or misunderstood the reference I made to Cooper, because you seem to agree with it.
But there is no such evidence that it has "virtually no difference... than any other service caliber" in stopping guys good or bad. Given the range of service calibers that's a large claim to make. The evidence that exists is that it penetrates in 10% ballistic gel and expands to similar depths as other service calibers in bullets that have been built to meet the FBI standards. That's the only source for the claim.
Trauma surgeons from major city hospitals have weighed in and cannot point to any additional damage done by the more "powerful" round.
Trauma surgeons have, in general, no idea what caliber folks were shot with when they come into the hospitals. They normally don't ask and don't care and no body informs them of it either. They are not trained to identify the effects of one round, one caliber or load from another. It is near impossible to tell.
I shoot it better (9mm); faster and more accurately than .40. I can carry an extra round or two in the same size gun. For me it is an easy choice.
As I said this is the correct approach. It's in this case that the 9mm is as effective as other rounds for self defense.
But it does not make the round more powerful than 45acp, 357 Magnum or 10mm. If a person can handle one or more of these calibers and loads effectively in self defense, they will have an edge on the 9mm provided other things are equal (shooters capability, proper bullet for the job, etc.)
I think fellas can find themselves in odd situations by arguing against the effectiveness of more powerful calibers and loads and even bullet selection. Why use the 9mm+P for self defense if all of these calibers and loads are so similar? To provide a bit more power is the answer.
tipoc