Some articles that gave me clarity. Yes, knockdown power and one shot stopping power in a handgun is a myth. A lot of research is done by Law Enforcement Agencies. They wont use something that won't work. FBI has reverted back to 9mm P.
Hi spekieries,
I agree with you on the "knockdown / one shot stopping power," in regards to typical handgun ballistics being questionable.
Over the 28 years that I was a Police Officer, I noticed there were usually two other starkly decisive factors, besides what calibers were used.
What usually proved time and time again to be the most important factors during shots fired confrontations, were almost always; WHEN and WHERE the looser was shot, not so much what caliber they were shot with.
That being said, as mentioned earlier in one of my typically tedious and wordy rants (not unlike this rant for instance), I believe the 9mm to be a somewhat adequate bad guy repellent, but only in the hands of that rare soul who can remain calm during an armed confrontation and thereby shoot fast & straight.
When I say "shoot fast," I mean before he shoots you and my idea of "shoot straight," with sort of borderline adequate cartridges is referring to throat, brain, spine hits.
So, if a person is not able to consistently get those types of hits under stress, he or she definitely had better learn to use a larger caliber and concentrate on larger area/torso hits when the armed bad guys bum rush him or her.
Regarding "when" - I have used a movie line to illustrate that point while training new Police Recruits.
In one of Clint Eastwood's old Spaghetti Westerns, as some gun slinger was busy threatening to kill Eli Wallach, old Wallach promptly shot the man dead and then declared: "If you're gonna shoot ... shoot, don't talk".
So, if you're ever confronted by Cop killers, armed robbers, etc., there is definitely wisdom in those words.
Related Topic:
It is my opinion that The FBI and other domestic Law Enforcement Agencies, choosing to issue the 9mm, typically do so for either political reasons and/or so that all of their members, including their petite ones, can run it through the quarterly qualification shoots that, these days include malfunction drills and such.
The 9mm recoil spring being a bit easier for dainty hands to compress under the stress of mean old mister stop watch.
In other words, my impression is that it's not so much whether the 9mm is adequate because, as adequate as it may be in the hands of a very-cool-under-pressure type of Officer or Agent, nonetheless history shows that cartridges like the .357 Magnum, .40 S&W and .45 ACP are noticeably even more so (it's a broomstick vs baseball bat thing).
This becomes especially obvious when shooting through car windshields and car doors (about 40% of all Police related shootings here during my 20 years with The Anchorage Police Dept.)
This is not to mention that in cold climates, people usually wear heavy coats and the 9mm definitely does not penetrate heavy clothing as well as the three above mentioned more powerful cartridges.
Also, cold weather reduces chamber pressure, equating to lower velocity.
Last but not least, more and more bad guys are wearing body armor these days.
In the tests I saw, the best of 4 cartridges tested for penetrating, was the 180 grain .40 S&W cartridge.
(All were done with Federal brand hollow points).
Incidentally, hollow point bullets are erratic performers, unless the hole is huge, the bullet is soft and the velocity is high, according to what I have seen.
9mm / 124 grain
.357 / 125 gr
.40 / 180 gr
.45 ACP / 230 gr
All that being said, I have carried a vintage Browning P35 in 9mm at times but, mostly because I was hunting rabbits with it, in the winter when the bears were hibernating, and/or travelling to and from the local shooting range with it.
Not wanting to carry a second/larger caliber handgun, while already carrying the full size P35, I just relied on the 9mm to get me through any potential bad guys that, might raise their ugly head at the gas station or anywhere along the road somewhere, etc.
Perhaps might stop for a pizza to take home, etc. (the damn zombies seem to be almost anywhere nowadays).
Likewise, I carried it briefly when I was a Narcotics Investigator, because my .45 was in the shop, to have it's worn down ejector and poor quality barrel replaced plus, Bo-Mar sights installed.
Parting Shot as it were:
Back in the 70's or 80's, LAPD quit their revolvers and issued 9mm Beretta Model 92 auto-pistols to it's general sworn members (Patrol Officers, etc.) but their SWAT unit all were always issued the Model US 1911 in .45 ACP caliber.
Along about that time, the Chief of LAPD had said something like; "I will not authorize large caliber side arms or hollow point bullets for my Line Officers because, too many of them have been mobbed, mauled and shot with their own weapon".
Incidentally, LAPD SWAT at that time, had successfully rescued more hostages by far, than any outfit in the World, Civilian, Military or Mercenary.
So, such elite outfits as The Israeli Moussad and US Navy SEALS, just to name a couple of the many, paid LAPD to train with LA's SWAT guys.
Those two LAPD handgun caliber concepts, as they pertain to defensive handguns for law abiding citizens, forward thinking enough to carry a pistol in these shaky times, should speak volumes on the topic of what caliber to choose.
Today as retired, I now work in Armed Security/plain clothes and am issued a Glock .40 and 180 grain HP ammunition.
But, not being much of a Glockster - On my own time, I usually carry my Sig P226 in .40 caliber with 180 grain flat nose ball or, my as mentioned .45 ACP - 1911 with 230 grain ball.
Walk softly and carry a big stick,
Velo Dog.
. I replaced the walnut grips with diamond checkered pachmyer rubber grips and by the time I left purchased a new gun a year later, they were pretty well worn flat on the right side. (they were on my right hip and that is the side the rubbed against everything.) Carrying my gun became a chore, and chores are better suited for tools that are designed specifically for them. Enter the polymer framed gun. Polymer is stong, somewhat flexible and hardy. It can be molded so it is cheaper to produce and cheaper to buy and stands up to the rigors of EDC that I went through. 
