Whenever the "caliber wars" arise, I like to present this excellent 2011 lecture by Dr. Andreas Grabinsky, M.D., who is currently a board certified Anesthesiologist and program director for Emergency and Trauma Anesthesia at UW Harborview (his time in Cleveland, at University Hospitals, actually overlaps my wife's time as a pediatric resident at UH Rainbow and my own schooling there, but this was before I developed a true interest in this sport/hobby, so, unfortunately, I never got to talk to him) -
He's a very good lecturer. I promise the half-hour will seem shorter.
My apologies for the fact that this video won't embed, so you have to click-out to YouTube, but some of the material is graphic.
My own view towards the "caliber war" is somewhat conflicted, but it can be succinctly summed up through a logical progression of considerations.
First, there's "no replacement for displacement." All else held equal, I'd pick the largest caliber I can, as the diameter of the bullet -provided that it stays together- is going to be the diameter of the bullet. As
@HansGruber pointed out, with modern defensive/duty handgun rounds, it's the permanent wound cavity that counts. All factors equal (i.e. if the bullet is a modern hollow-point, that the pedals open to the same extent from one bullet to the other), a bigger bullet should cut a bigger path.
This is really the only area where I have a problem with what Federal's article cited in the OP - in it, the author notes:
An attacker hit in the vitals with a 45 Auto is no more incapacitated than one hit in the same spot with a 380 Auto.
This is demonstrably false - more tissue destruction simply will result in more/faster physiologic fallout, be it severing a crucial nerve that enables muscle function or by simply causing more/faster blood-loss with more organ/vascular damage (leading to hypovolemic shock - i.e. "passing out"). Yes, for all intents and purposes -as demonstrated in Dr. Grabinsky's presentation above- "all handgun rounds suck equally." But even slightly more damage is just that much more damage.
In "a game of milliseconds and millimeters," as John "Chappy" Chapman -noted SME in CQB and a member of the BCM Gunfighter cadre- likes to say, if that bigger bullet can buy me just that fraction of a millimeter more, well, who am I to not want to take it, right?
If I would suggest that anyone *not* draw their gun for even 0.05 seconds after the threat that they're facing down was allowed to draw it, I'd be slapped silly, wouldn't I? The same logic applies, here.
However, due to what is most likely going to be increased recoil (more mass, more powder, etc.) and typically lesser magazine capacity as a result of the increase in caliber, I must then concede to the reality of whether "the juice is worth the squeeze,"
for me: i.e. whether
my objective performance with that specific weapon (and here, it must also be noted that the weapon in-use has to be held "the same" across the calibers as well - i.e. a Glock 17/31/22/21/20) indicates that I can be as effective with one caliber (and/or load) as I can another. Bigger calibers and/or hotter loads will exact a bigger strain on the shooter in terms of recoil management, and that's just pure physics.
I really see this second factor as being huge.
So instead of me jabbering on about it,, here's a favorite excerpt of mine, by noted terminal ballistics expert
DocGKR , as he posted on M4Carbine.net a few years back. Here, he recounts a conversation that he had with a true gunfighter -
DocGKR on M4Carbine.net said:
In a timely coincidence, a very experienced senior SOF NCO who has slayed many of our Nation's foes and who has the distinction of having used 9mm, .40, and .45 ACP pistols in combat during various phases of his career wrote the following superb analysis discussing this very topic recently:
Not getting into the weapons transition issues from frame design to frame design (it's the reason I love to hate the Glock), the fact of the matter is that the recoil on the 23 crosses the magic line of running the **** out of your pistol.
Allow me to explain...
Most of the guys on the G19 thread mentioned that they can handle the reduced size of the 19 and the recoil increase over the 17 is acceptable. Most of us have also determined that this does NOT cross over to the .40 cartridge. Guys with a firm handle on recoil manipulation can use the 22 and 35 with acceptable results. However when you go down to 26's and 23's, the juice is not worth the squeeze. The recoil is now noticably effecting times and it's measurable. If you can't effectively control recoil and are wasting time allowing your pistol to settle between shots then this is all a wash and means nothing to you, but if you can apply the fundamentals effectively you will quickly see that you can't run a sub compact 9 or a compact .40 worth a ****. So a decision to accept a larger pistol in order to have an acceptable recoil impulse based upon caliber must be made. The smallest 9mm Glock recoil that I will accept is the G19 and I will not go below the G22 when bumping up to .40.
What this all this then combines into is the ultimate truth that
@Talyn summed up in a few words -
Regardless of the cartridge it all boils down to shot placement.
^ And this is where the buck stops for me, too. If I can't *-repeatedly-* hit what I'm aiming at, in rapid succession, then that's a problem for me. Shot placement is king, and I want as many of my shots there as I can, as fast as I can.
I'll take the largest caliber that I can shoot well, and fill that magazine with as many bullets of proven terminal performance as I can, and vet the gun for function and performance with said ammo.
A lot of people say that they shoot a bigger caliber/hotter load "just as well" - then you ask them if they've actually put themselves on the timer, against a known metric or shooting against a known Standard, and you never hear back from them again.
No-one likes it when the person they're debating asks for actual, hard proof: it's that call for the quarter mile slip to be put on the bar that just kills all the bench-racing.
When it's time to pony-up with proof, a lot of folks would just rather pretend they didn't see/hear it, rather than doing the honorable thing and admit that they're bragging or just plain wrong.
To make this assessment for myself as objective as possible, I will shoot scorable standards (time/distance/score). Provided that I'm being honest in my efforts, that data won't lie.
The eternal debate is between shooting a big enough bullet versus shooting it fast enough (as many of my instructors like to say, "anyone that deserves to be shot deserves to be shot more than once") and well enough (shot placement) and having enough of it (ammo capacity). There's no right or wrong answer to this one, and each person needs to find his/her own compromise. Maybe one's line of work presents with intermediate barrier considerations. Or maybe another shooter lives in an area that imposes ammo capacity restrictions. These are all real-world considerations can well shift that balance.
However, the physics are undeniable, and the data won't lie.
