by David Tong
Gun writer, David lays out the case why . 40 Smith & Wesson ( aka 40 S&W ) ammunition is still a go-to caliber for law enforcement and self defense.
U.S.A. –-(Ammoland.com)- Is the .40 S&W still a good round? The short answer of course is “yes.” I would agree.
There have long been questions regarding the reason the .40 Smith & Wesson cartridge has been losing popularity, even though as of as late as 2011, some 65% of American law enforcement was carrying a pistol chambered in the round.
Its gestation has been so oft-repated (Miami 1986 FBI shootout, insufficient penetration of one 9X19 Winchester Silvertip, and so on) that I won’t add anything to that discussion.
American LE agencies are looking for several things in a duty handgun. Accuracy, economy of both ammunition and handgun, adequate light-barrier penetration for ISO 1 wood framed buildings or automotive sheet metal and glass, reasonable recoil levels for non-shooting recruits that are not firearm saavy, and consideration to magazine capacity.
Several things happened in 2016 that some pundits suggest are the death knell of the . 40 S&W.
- First, during the Army handgun trials, it was determined (mostly) that the new Modular Handgun should retain 9mm NATO (9X19) caliber.
- Second, the US Army Delta Force and Navy SEALs both adopted the Glock Model 19 as their official service pistol.
- Finally, the FBI, whose reticence about the 9mm in 1986 ultimately led to their advocacy of the .40 S&W, had an about-face and returned to 9mm thirty years later.
Their reasoning, which has a marked impact on LE agencies who typically follow the FBI’s logic in terms of both forensic review as well as logistical concerns, was that none of the main three defensive pistol rounds, 9mm, .40S&W, or .45ACP, had substantially different wound profiles or “stopping power,” the latter they termed a “myth.”
They additionally stated that the softer recoiling 9P was going to be easier to train personnel with, cheaper to offer cash-poor departments to practice with and issue duty ammunition to the troopers, and overall made more financial sense with what might be perhaps greater round count longevity with whatever pistol was issued.
What was once Glock’s primary advantage, being able to purchase one of three main grip frame and slide sizes for detectives or uniformed exterior carried patrolmen while being able to use the longer magazines in the smaller pistols is no longer something they have alone. Indeed, most manufacturers including Smith and Wesson have essentially produced substantially similar handguns of different lengths and weights as well.
How this boils down, to me, is this. Most people consider the .45 “too large” a pistol with a large magazine of 12+ rounds, and the raison d’etre of the .40 was to offer a 9mm sized pistol carrying 12-15 rounds of ammo, rather than 17-20 9mms.
Why take the reduction in capacity? The perception that a . 40 Smith & Wesson still has advantages in expansion and penetration, the two key points agencies look for in actual performance.
. 40 Smith & Wesson Ammo Testing
The website, www.luckygunner.com/labs has what is currently the most detailed exposition and testing of these three rounds capability with the FBI heavy clothing test model over synthetic ballistic gelatin. When one compares the best possible 9mm rounds versus the best .40s, the . 40 Smith & Wessons provide a shade better of each, while the best .45s are a tick better than the best .40s.
In short, a pretty “linear” result, given like-for-like levels of cutting-edge development and technology exerted for all three rounds.
Despite some folks stating that 9mm having a reputation for class leading penetration, the .40 Smith & Wesson and .45 demonstrated yet more in the Lucky Gunner tests. There is however a balancing act – those rounds that penetrate greater generally expand less, and vice-versa.
An urban officer might not have quite the same needs to put bullets into a vehicle, compared to a Forest Service Ranger who might have to put down an aggressive bear or cougar, for example.
Another recent You Tube video on that discussed .40S&W and did a pretty good job was Army veteran Paul Harrell’s comparison of two Glocks, a Model 17 9mm and Model 22 .40, of the same size and profile. His informal solo test showcased a variety of current ammunition, and while the time elapsed for accurate rounds on target for 9mm was a bit shorter, he advised the viewer to make up his or her own mind when the .40 Smith & Wesson showed superior penetration and expansion and whether the extra second to fire six to eight rounds was that big a deal.
In my own hands, I do tend to agree that even in a full-sized pistol that the .40 Smith & Wesson does have a recoil pulse that feels “sharper,” though I would hesitate to label it “harsh.” I have also fired the .40 in the SIG-Sauer P229 and the S&W M4006, both all metal hammer fired pistols, and I did not find the recoil bad at all, certainly not enough to bother me.
What continues to draw me to the .40 S&W is the variety of bullet weights and velocities that you can fire in it. The 135gr at 1250fps, the 155 at 1150, the 165 at 1050, and the 180 at 950. Each has its place, as the lighter bullets generally offer greater dynamic expansion and reduced penetration, while the heavier offers the opposite.
Thus, the .40 Smith & Wesson remains a good choice and will be around for decades, as all American LE or military rounds do. The FBI may think it’s a great idea to return to the 9X19, but that doesn’t mean we do, especially if prices on clean used pistols and ammo for the . 40 S&W remain momentarily somewhat depressed.
Some major details overlooked. Talking about weapon/ammo selection needs must be based on mission assessment. Is the weapon to be used by FBI/LE? Military? For personal self defense? That makes a lot of difference. For military a pistol is used only when the long arm is out of and until it can be returned to action. A police officer has to be able to defeat auto bodies/glass and some building materials. Either should be able to have and deliver ammo through a protracted gun battle.
The citizen on defense specifically does NOT want his/her/whatever rounds punching through some neighbor’s car, walls or windows. Also they should hopefully be able to disengage after a very few rounds expended through retreat of either themselves or the bad guys. I am now 62 and a CCW carrier. That said, the old soldier (7 yrs US Army) still likes to have a couple back up mags just in case. It’s a comfort factor rather than any real perceived need. I also carry a G23 .40 S&W as a compromise between larger round than a 9mm and a greater round count than a .45acp. That’s just a matter of a personal choice rather than any great conviction to change anybody else mind on things.
I’m buying a 9mm sig legion p226 strictly for range duty, also I want a cool looking gun with an optical sight. My daily carry is .40 s&w sig p229. I like the 40 because of better penetration and the round was designed as a hollow point. I’ve owned a bunch of sigs, p380, p226, p229 all chambered in 40 s&w. All have been extremely accurate out of the box. My favorite sig is a stainless p226, heavy as hell and groups 3 inches at 50 ft. It lives in the boat when we go off shore or to the Bahamas. When work takes me to bad neighborhoods I like my p229 tucked next to the seat in my truck.
I like 40s&w so all my pistols are 40’s, I’m buying a 9mm because my friends all shoot 9mm and it will make range days more convenient.
Big point that I rarely see with the FBI. The FBI sent a few agents to their death in the Miami Shootout armed with pistols when the bank robbers/spree killers had a Mini-14.
The FBI now has dedicated FBI SWAT teams in the big US cities. “56 field offices” So- unless you are a white collar criminal accused of moving numbers into the wrong column- you will probably be arrested by FBI agents who look like they are storming Bin Laden’s secret mansion. These guys might have 9mm’s but they are holding AR-type rifles in your face, not pistols.
The 9mm’s are for the guys/gals in suits who will have a higher aggregate marksmanship score than if they had .40’s or .45’s.
All I know is- I have a .40 next to my bed
Delta were using Glock 9mm back in the early 2000’s. Switched to .40 later on. Vanilla SEAL teams started switching to Glock 19s late in 2015 way after everyone else. Army SF have been using them for years. Everyone lost their shit when SEALs switched over because hundreds of thousands of retards think SEALs are the be all, end all of SOF.
They also follow the FBI off the cliff. Was blogging somewhere else and a fellow put forth to have all your handguns take the same round. I think he said 9mm for handguns. I cautioned that during the ammo shortage the only thing in the shelves was 40 and I said I was going to buy a 40 Handgun to spread the risk around just in case. He responded that where he was 22 was the only shortage. Maybe the every round shortage was just in Maryland, PA and VA but I doubt it. I have 9’s, 40’s, convertible to 357 sig, 38’s, 22’s and 380’s I think just having one type gun in one caliber boring if not shortsighted.
I have a .45 ACP and a Raging Bull .464 Causal Revolver, as well as a .22 with a Suppressor those are my handuns, my preference for CCW is my .45 ACP.
Every once in awhile I get bitten by the “gunbug” and want a new gun. Last time I wanted a 1911 and I got one. I thought I wanted a .357 revolver but, realized that they are very outdated. I came to the conclusion I wanted a polymer pistol. Then I came to the conclusion I wanted an M&P 40. I haven’t shot it yet but, WOW, does it feel “right” in my hand !! Videos like this make me feel confident I made the right choice.
I know this really late, and im stumbling on this article, and specifically your comment months late. But Im curious to know, How is a 357 Revolver outdated?Modern Revolvers are just as capable as modern Semis, just with a drastic reduction in capacity. Modern Revolvers still do their job just as well as any Semi
For self defense you can get a Taurus .357 with an 8 round cylinder
I was waiting for somebody to bring this up unless I’m missing something the 40 Smith & Wesson is more powerful than 9mm or 45 ACP in standard pressures non + P loads.
I have a 5 inch government all Steel 1911 I’m getting chronograph readings with Underwoods 155 grain loaded with a XTP bullet=1375 fps = 650 ft lb of energy. Recoil is mild in the all Steel gun with the correct holster super easy to carry.
45 takes care of every thing,40 okay so in the middle,9 is for people that can,t hit nothing,i am a cop,25 years in the army rangers,stick with a 45 period it will do the jb every time i know i have several bad guys that would say yes if they could.
I did notice one thing during the ammo shortage a few years back while looking for 9mm in vain was that .40 S&W was on some shelves. I bought a Glock 23 with that in the back of my mind. The GLOCKS in .40 have an added advantage of with a barrel change .357 Sig and 9mm are possible. .357 is a hoot to shoot and a good if underrated round.
It is a fact that mass and inertia no longer have meaning. Every bullet is now evaluated by Kinetic energy formula and jello.
That six mile across meteor that killed off all the dinosaurs would have done the same no matter the size.
The FBI is full of accountants that believe what they read. I went to a FBI self defense class in about 1970 and they were teaching wrist locks and finger locks as if it was good self defense. Obviously they were reading the Bruce Tegner books of that time. And for Riot control the were teaching ancient Greek wedge and diamond formations that did not work in real riots using nightsticks, with hippies throwing rocks. Maybe if police were issued the Greek spears.
If only the 9mm could shoot 180 grain bullets.
Why is everyone spraying bullets nowadays. Cooper warned you. Deep inside you wish you had a 45.
How would you like to shoot a 76 grain .45 at 1700 fps with 466 lbs energy. Tremendously less recoil and greater terminal ballistics. Currently selling to LEO’s but consumers should be ready in 2018. SIMX Ammo. 100% polymer core.
ACX polymer/powdered copper bullet now available, and it is deadly effective in 9, 40, or 45. I am considering the CZ compact in .40 since my nanny State mandates 10 rd mag max. Otherwise, I’d give the hi cap 9 a really good look. This, after 30 years with the 1911 series 70 Colt. I think the new bullet may be a game changer.
Read the History of this action by General Arthur MacArthur father of General Douglas MacArthur, you will find out different there are several books about this in Military History regarding the Moro Insurrection after the Spanish American War of 1898. I have read close to 25 of them as well as the Military Official History of it, and you need to do some more research. And No I was not a flag officer, I just had the fortune of being in the right place at the right time and had just re-enlisted for another 6 years four months before my 55th birthday and under special dispensation of the Chief of Staff US Army I was permitted to serve out that enlistment.
If most people pay close attention of what’s going on in the world they would find out the, “agencies” mostly get their hardware worked on by the USMC at Quantico… Which makes since being that the Marines’ primary tasking is killing people and blowing shit up! So, if you want answers, seek he that does the WORK!
Many civilians also fail to understand that agencies all go with ONE MAKE/TYPE, ONE CALIBER so as to allow interchangeably amongst compadres during a gun battle or any other times. (Cost effectivity)
You may also notice that the Marine Corps has thier .45’s back and they are very happy with that!
If this is a beancounter move,(anything is possible) that kind of thinking gets people killed! They talk about training cost, how about training a replacement? Give them adequate weapons and good training. Didn’t learn from Vietnam? Those who do not learn from history repeat it with lives lost! If 7 out of 10 bullets s expand let me take my chances with a larger bullet th begin with. 9MM wants to expand, 45’s never shrink.
When the Marines were in Vietnam, we were winning. Did the bean counters tell you that little fact?
I am 73, 100% Disabled Nam Vet and Retired from the Army, I still carry and prefer the .45 ACP. I have seen people hit with a 9mm who were on PCP and they kept right on coming, yet I have also seen some really big men on PCP get hit with a .45 ACP Military Grade Ball round and go down and not get back up even if not a kill shot. Personally you can keep you 9mm, as for myself, I have carried both the .40 Cal and the .45 ACP I now carry and after 42 + years in the Army and still alive, I think the .45 ACP will do what the 9mm will not do, the 9mm does not have the knock down power of the .45 and neither does the .40 cal, sorry boys but for my peronal safety and that of my family the .45 ACP does it.
Knock down power? Doesn’t exist. SMH. I’ll take capacity any day.
He’s not talking about the person actually being knocked over. Anyone with a third grade education understands the penetrative nature of the bullet will cause it to pass into or through without knocking down, so especially a man like him. What he’s saying, because you want to pretend you don’t understand so you could scrabble to make that over-cycled, redundant point, is that in real combat, of which he’s probably seen more than 99% of the people here, he’s seen more people put down or put out of combat ability, with .45. And I can’t agree more. 2 years of recycling weapons off the jawas in Iraq, compared to my issue gear, means I can’t agree with him more. Ain’t no replacement, for d-ee-splacement. Learn to hit what you shoot at when it’s actually moving or worse, firing back, and you’ll agree. I’ll take a few less .45 over 9mm anyday and bet my life on it. Oh yeah, I did. All the time. And here I sit, alive and able to post these snyde remarks.
I was in the military also USMC but I was only in for 9 years. 42 + years what are you in Four Star General. And you don’t know shit it has been proven knockdown power does not exist only in the movies. And it depends who’s getting shot the good guy or the bad guy. 9mm 40 45 the all capable of Defending you all about placement….. Placement ends all battles
Knock down power is a Military term, meaning the ability to take someone out of the fight. Evidently your DI did not explain that term to you, during the fighting in the Philippines between the US Army and the Moro tribes the Army had asked for a firearm that could do the job that the .38 Special could not, which was the standard sidearm issued to Officers and Senior NCO’s of the time. Colt had been experimenting with what became the Colt Model 1911A1 .45 ACP and after extensive testing by the Army between 1898 and 1901 awarded a contract to Colt for the Model 1911A1. It was determine that even whe hooped up on drugs the 1911A1 would and did remove the Moro tribal warriors from the fight, and in more then a few cases did in fact Knock the over backwards. The round does not pick you up when hit by it it simply takes you off your feet and on your back or butt. It is also a fact that getting hit by a .45 ACP is like running into a slow moving freight train, with the same result you are out of action.
Actually it was the woeful 38 Long Colt round. SA Army .45 Colt revolvers were taken out of storage and issued which helped. I don’t think the .45 ACP in any semi-auto pistol made it to the PI insurrection. The .38 Special is a more powerful round developed later.
The weapon used in the Philippines between 1898 and 1901 that they requested to stop the Moro Tribes was in fact the .45 Long Colt revolver. Surprisingly the 1911 came out in 1911.
Glad to see my old S&W 4006 mentioned in a post. A real steel .40 pistol is comfortable to shoot and hits hard as hell w/ 180gr defensive rounds. The downside is the weight. Here in FL w/ shorts and tee shirts the regular dress, it’s hard to conceal a full-sized large caliber pistol
Bill,
I find the HK USP Compact .40 to be excellent for cc in shorts. It’s light enough to not strip off your jimmys with a belt on, but heavy enough to tamp down that recoil. I find with heavy 180 pdx1s it’s about as accurate as anything I’ve ever shot, out of that reduced barrell.
Didn’t you get your general issue over-sizes Hawiian Shirts when you moved,down there?
In my opinion bigger isn’t always better. Some calibers perform better than others, but how many of us avid 2A supporters need to penetrate windshields, car bodies, level IV body armor wielding jihadists, etc. Carrying is to each his/her own, but you will always perform better with a firearm that you are more comfortable with. Aside from an assailant being hopped up on some incredibly fantastic stimulant any caliber handgun when properly applied to the upper thoracic region is enough to make said assailant review their actions about what they did to get shot in the first place. Remember a handgun is a last ditch defensive weapon, not offensive like in all the Hollywood movies. The best means of personal protection is to make yourself a hard target, keep your head on a swivel, know your surroundings, avenues of egress, and points of cover. Remember though should trouble find you the first rule of a gunfight is always have a gun and the faster you finish a fight the less shot you will get.
I agree, I’ve had my ccw for 30 years never had to draw or even had to consider drawing it. The best defense is to not
make yourself a target, it’s the whole “brains over brawn” thing.
I took a class with a guy who worked as a Cop on an army base here. He told me that the 9mm would bounce off the severely raked windshields on modern automobiles. He also told me he had personally been in a situation where a 9mm round BOUNCED OFF a heavy leather coat. For those and other reasons he carried a .40 (165gr Speer Gold Dot) as his personal carry piece. Like me he is a big guy and a Glock 22 works fine as a concealed piece. I have a Glock 22 and a Jericho 40. I don’t use the Jericho for concealed solely because the hammer digs into me.
i can only hope that idiot comey had nothing to do with any fbi firearm decisions
Notice when the FBI went to 9mm it was like a game of FBI sez. Never seen so many lemmings abandon their 40’s-police agencies, civilians you name dropped their 40’s. So is the recent dropping of 40 cartridge price a clearance sale or permanent. That being said the 40 is a snappy round. Today I fired both out of Glocks. The 9 did better groups and back on target faster. But I rarely (train?) further than 7 yards so the 40 groups were still acceptable (165 gr. vs 124) However I really like .357 Sig a slight reduction in recoil large increase in power, actually a 9mm on steroids. Unfortunately it is unpopular therefore expensive.
Im gonna stick with 9mm. More capasity and better penetration
We just showed you in the video the 40 had more penetration watch the video again evidently. And more capacity 17 vs 15 that’s two bullets. You’re going to need more than two extra bullets with your nine. Even when he shot the concrete block the 9mm 15 bullets 40-cal 8. Nothing wrong with the 9mm do stay with it but after watching the video how can you say the 9mm have better penetrator did we watch the same video???
John I forgot to mention that shooting the 5.7 is sweet as it has recoil comparable to a 22 mag. It shoots
A 40 grain bullet in excess of 2100 FPS
Generating 391 foot pounds of energy which
Is comparable to A 40 caliber in energy
Thanks again. I do wonder why we’re still using essentially the same technologies that were available 100 years ago. the materials have changed, bullets have certainly improved, auto pistols have been mostly perfected, but the top cartridges are pretty much ballistic remakes. .40 S&W is essentially the .38-40. 9mm, .38 Special. .45 ACP, .45 Colt/Schofield. The last two are themselves from early in the 20th century. The Excel Arms MP 5.7 looks like it would be a perfect choice (it resembles a Browning Buckmark), but I can’t speak to quality as I’ve never handled one. Ironically, their factory is about 35 miles from me, but none of their products is legal for sale in California. Of course, if Sacramento gets their way, the .31 and .36 Colt and Remington pocket models might be making a comeback here.
AS I’ve said many times before it’s not the caliber of the gun but the caliber of the person using it.
Roy. I can not interpret the meaning of your head shaking. Whaaat?
The “head shaking” is a reaction to witnessing a discussion I have seen many, many times before in the last fifty years. The more things change, the more they remain the same.
When I see these discussions I just shake my head and smile.
One area that .40S&W has a distinct advantage over the 9x19mm is in ball ammo effectiveness. All .40S&W FMJ bullets have a wide flat meplat, such designs are rare with 9mm ammunition. Wide flat point ammo provides straight penetration and maximizes the wound channel of non-expanding bullets. The narrow round nose profile of most 9x19mm FMJ ammunition, in contrast, minimizes the wound channel profile and very often veers away from straight penetration.
Bottom line, when FMJ ammunition must be pressed into defensive use by law or necessity, the .40S&W becomes a clearly superior choice.
The 9mm proponents like to say how much cheaper the ammo is- but the +P hollow points they say test well are certainly not cheap.
Right know I have about 20-50 hollowpoints of 9 mm and .40. And hundreds in ball. I imagine I’m similar to most pistol owners.
So- a 9mm owner is shooting ball but carrying +P HP, hmm- anyone else see a problem with that?
They’re all good. Buy high quality ammunition and practice with what you’re comfortable with.
I liked my M&P 9mm so much I grabbed the .40 and then the .45, all full size and police trades from Buds
at a fraction of the cost of new in box, with three magazines and night sights with 50% life left.
Buyers market thanks to federal and local governments buying more new guns.
I also like the M&P 40 as well as the 45.
I also carry a high capacity 9mm and sometimes a 380. I carry based on where I’m going and weather.
My point is that with today’s new defense ammo it has
Definitely improved ballistics where I feel comfortable
When I carry my Glock 380. I do regularly practice
With the pistol I wil be carrying due conditions. But
Most important of course is bullet placement. That is
The deciding factor in any gun fight. So keep going to the range and stay safe.
I’m with you. I have an SD40VE in 40 and a PT111G2 in 9mm. My carry ammo is Hornaday Critical Defense. I carry the 9mm concealed and the 40 open in the summer. In jacket weather I carry both concealed. I run plenty of ball ammo through the guns, but I also shoot the CD because it’s slightly different. Yes, it costs more to train with the carry ammo, but it is worth it in terms of knowing how my gun acts with it. I find the Hornaday Critical Defense ammo reliable in both weapons. It’s not uncommon for me to have both guns on me.
The one thing that is also a big consideration is ease of training and pistol life. The .40 is hard on guns. Slide speed is high, which also translates to a snappier recoil impulse and reduced pistol life. Watching that happen on hi-speed video is pretty remarkable. I do LE wound ballistic workshops for a major ammo maker.
The one thing not mentioned is also the improvements in bullet design/performance in 9mm. Shot placement is still the key factor with penetration being the next most important criteria. Expansion is expected ( at least 1.5 x’s original diameter) but is the one thing we have least control over due to target barriers. Things like clothing, windshield glass, drywall and sheetmetal all have different affects on terminal bullet performance. I carried a .45ACP for over 39 years. I now carry a 9mm. I think round count is a more important issue than ever before due to the “jihad” going on and I’ve personally witnessed the improved performance of the current 9mm ammo.
Given your experience in this area, I’d be interested in your opinion of rounds such as the 5.7 x 28mm and .22 TCM.
John D. I have owned a 5.7 for 8 years now and I have found it to be an excellent shooter. Ballistics on
it are pretty good. Some compare it to a 22 magnum I personally rate it a lot higher than the 22 mag as it does more damage the 22 mag does not lift a filled 5 gallon bucket off the ground the 5.7 does.
Plus I personally can hit a human size target at 200 yards off hand, 50 yard shots as well as 100 yard shots are all in the kill zone off hand shooting with open sight.The big plus is that fully loaded with 21 rounds, it weighs less that a standard 9mm loaded with 8 rounds
Thanks for the info. I was trying to find a replacement for my mother’s revolver, which has a trigger pull that has become a bit too heavy for her (she’s also become more recoil sensitive – carpal tunnel). It’s become largely pointless, however. Here in California, there will be no handguns for sale after 1/1/18, something I discovered today. I had mistakenly thought the de facto handgun ban would apply only to semi automatics. That does not appear to be the case, since the language of the unlawful law in question might be interpreted to include all handguns. Still, the information may prove useful anyway. There is already a thriving black market. That’s how Moonbeam and all the other little Caligula wanna be’s in Sacramento wanted it, though. Citizens have rights; criminals, not so much. Given all the egregious “laws” and regulations they’ve foisted upon us this year, I fully expect that unless Jeff Sessions steps in, there will be a full blown insurrection here before the end of the decade.
Well stated. Particularly, that “shot placement is still the key factor.”
I have shot quite a bit of small game with both rounds. I will stick with the .40. No comparison with the right ammo.
You forget to mention lucky gunner used sub compact pistols in their comparisons, 40s&w performs better with barrels that are 3.5 or longer best comparisons are at ballistics101.com
What ammo are the Teams & Delta using? What were their points for the change?
Since they are military and under Declaration III of the Hague Convention of 1899 rules, it would have to be FMJ ball. Probably standard NATO stuff.
Granted, there is a caveat in the Hague Convention that allows use of other than ball ammo on nonsignatories, which would include paramilitary or nongovernmental fighting forces. Also for military police use.
I’d imagine that the SF guys aren’t utilizing their sidearms for the majority of their encounters though either.
Is it still good? Dunno. You’re going to have to pull some bullets and smell for spoiled powder to determine that. You know, the same way you tell if milk has gone bad … smell it.
when the government makes a decision such as this one people always forget the cost factor. large government needs to save money, agencies are asked to cut costs and this is one way, so the cost savings of moving 100% to 9mm across the board becomes a important one. this is the old bean counter argument.
this move from 40 to 9 was a bean counter move – only a saving in price per round, and a slight cost change in pistol price. no training cost change, however there is the old “ammo interchangeability with allies” used with the 45- 9mm switch in the military – that was another bean counter move- that gave you extra capacity the same ammo interchangeability but in reality just made the USA on the hook to provide said ammo to the allies.-