One of the reasons why some enemy combatants don't go down after taking several 9mm hits...or 5.56mm and 7.62mm for that matter is because a lot of the insurgents can take so many bullets is because they are usually doped up on heroin. It allows them to feel little or no pain after being shot multiple times...though this is hard to prove.
It's hard to prove because it's a load of rubbish. If you're hit in the "T" (draw between ear to ear and down to your chest) you are going to drop. No matter what substance you've taken. Simple as that. Whether it's 9mm, .40cal, .45cal, 5.56mm whatever. Heroin ain't going to keep you alive (let alone fighting) if your heart, lungs, spine or brain has been hit.
Pistols are inaccurate weapons at the best of times and are a low priority for a soldier. They are designed as a last resort for military purposes and their ineffectiveness is recognised by the fact that many "traditional" pistol users in the military (tankers, pilots etc) are starting to carry carbine rifles (M4's, F-88C Steyrs etc).
People have also allegedly complained about these rifles performance in Afghanistan etc and about the "effectiveness" of 5.56mm rounds in general.
Anecdotal evidence is that 5.56mm rounds are less lethal in reality because they tend to "over-penetrate", meaning that if they don't hit bone or a vital organ they don't do as much damage as other calibres. (That they tumble but go straight through without causing a particular severe wound, is the allegation).
The requirement for the SS109 round was to penetrate 12mm of plate steel at 500m's. Any round that can do that is plenty powerful enough to be lethal against a human being.
What is lacking is marksmanship ability... M4's don't help this at long range because of the shorter barrel length. If they are being employed in a role for which they weren't really designed, then what's to blame? The tool or the user of the tool?
