So, I feel like most people who debate this have never actually seen a gsw, so are there people on here who have real hand experience and what are your opinions?

I have read that CHP preferred the .40 over their 357 mag because it was significantly more effective. Now my friends department is switching from 124 HST to 124 GD because they were more effective in their collection of OIS. How can there be no difference between 9 and 40 but there is a difference between two good 124gr loads? Modern 9mm still doesn’t equal 357 magnum of the 2000s so if 40 was better than that than wouldn’t it still be better than 9?

Personally I have seen a lot of GSWs and to the abd/chest yeah I can’t tell the difference, but man some of the ones to the legs or arms seem worse that others.

Is there really a reason to go with 9 instead of 40 if you can shoot 40 well?
Do you honestly think 9 is as effective as 40 against attacking dogs? Mountain Lions?
I don’t know, but I am tempted to carry a 40 when hiking, unless people here really do think that 9 is no difference against things like mountain Lions?
I shoot both 9 and 40 well, ammo is about the same cost, mag capacity is similar enough.

I know technology has made the 9mm a lot better, but does it really equal the 40?

Sorry to bring this up again but it’s hard to find responses from real world events, not just “gel says this” or “yup no difference”. Can we get some real stuff to read on this???

Well, they are both pistol calibers so both are underpowered. Shoot what you can hit with.

I have seen my fair share of gsw (gun shot wounds) in my 35 year career as a LEO.  My opinion, shot placement trumps everything.    I've been to autopsies where 22 LR was fatal.  Little bullets go in and follow path of least resistence and can do a lot of internal damage.   Victim might be mobile for considerable time until blood pressure drops.   Central Nevious System and Shots to the head are effective but is really dependent on where the bullet hits.    Drugs/Alcohol and physical state of the person shot can have a huge bearing on whether or how quickly a person stops after being shot.

I put way more faith in tactics and my ability to hit the target than the difference between any handgun cartridge.   Train with what you carry, keep your eyes open and don't go places where your likely to get into confrontations.   Have the mindset you will survive and don't be afraid to back off from dangerous situations.

I've carried 38/357, 32 ACP, 380, 9 MM, 40 S&W and 45 ACP as a LEO.   I've seen people shot with everything from BB/Pellet guns to handguns, shotguns and high powered rifle cartridges.   If I know deadly force might be required I will take a long gun, preferrably a rifle.   Shotguns work if your close with the proper ammunition.   The type of bullet has an effect on rifles as well as shot placement.   Nothing is a death ray, you still have to hit the target in the right places to be effective.

If you like the 40 and can use it effectively more power to you.   If your required to use deadly force then shoot till you or others are no longer in danger and the threat is stopped or has vacated the area.

Life and situations can be very unpredictable, you have to respond appropriately for the situation.

First rule of a gun fight is to have a gun.  A 44 Mag under the seat of the car does you no good if you can't get to it if you need it.   A 32 or 380 is better than no gun in a deadly confrontation.    I have several firearms I use for defense and I use which ever firearm is most appropriate for my day to day activities.

^This

p.s. thank God you did not compare the body dismembering .45 acp

The thing that gets me. Is 9x19 will penetrate barriers better, and has more capacity. Taking into account ammo like Gold Dots, Ranger, and HST, the wounding potential while greater in .40, isn't so much that it negates the advantages of better barrier penetration and capacity imo.

I would make a case for .45acp HST vs any 9x19 in a self defense scenario outside of LEO or .mil where barrier penetration and capacity are far less critical and your attacker is far more likely to be much closer. But, your talking duty use, so I would stand by my above statement.

This!

I often give hitch hikers a ride, but I also have a LCP under my left thigh when I pull over.

Thanks y’all,
Yeah I do think the better tactics and training have helped the effectiveness of the 9mm. I’m sure if 15 years ago people trained like they do now the 40 wouldn’t have felt as needed.

What sparked this mainly was my interaction with 3 dogs. They came at me aggressively and luckily I didn’t need to shoot one, but it made me think maybe I’d rather have a G22 on me than my G17? But it’s probably all in my head and 9 vs 40 won’t matter?

Cite?

Last LE range I qualified with both 40 and 9.  I have used the 40 for years and choice of ammo makes a huge difference in both calibers. (often its the departments choice re which ammo) I look at the energy the bullet has and like a 155 gr 40 and a 124 gr HST +p  9.  If I was in bear country I might carry a 44 mag --- but rifles have significantly more energy and for critters 300 WM sounds like a better choice.  As for real world trauma I have seen people die from even small calibers and survive even large calibers it depends on where it hits.  And I'm becoming more comfortable with a 9 but as we head toward limited 10 round mags in many states that may eliminate the high cap mag advantage of the 9 and the 40 and send us back to .45acp the wider it is the more the chance of cutting something that matters.

1. Shot placement is king, shot repeatability is queen, caliber is the court fool. If you shoot both well, 9mm gives you more rounds to hit them with and less recoil to slow you down between shots. Even if you shoot a bigger caliber well, less recoil is only ever going to improve your shooting.

2. Yes and no; with the wrong ammo, they'll both suck equally. With the right ammo, the .40 wins thanks to the ability to shoot heavier slugs. Nonhuman animals have thicker/tougher hide and tissue than humans, and good penetration becomes more important (whereas with humans, OVERpenetration is generally the issue and you want to go the other way). Most defensive pistol ammo performs very similarly in this arena, thanks to the FBI recommendations being used to standardize the industry, but with a hard cast round you can go well beyond those numbers and into "predator protection" territory (think 30-60 inches in gel, not 12-15).

3. Continuing from #2, load a heavy hard-cast round in either caliber and they'll be fine against mountain lions, with the .40 having an edge. Momentum is the name of this particular game, so you want big heavy projectiles, and .40 wins there. When I hike, I carry .45 Super 255gr hard-cast rounds.

4. 9mm is slightly cheaper, slightly less recoil, and slightly more capacity. No one point is huge, but a bunch of small improvements add up to a more effective defensive pistol cartridge.

I don't like comparing cartridges in terms of "better" without context. They're both tools with specific qualities; pick the one that's "better" for the job you want to do. I like 9mm for human protection, because thats all about lots of bullets fired accurately and quickly. If I want big and heavy for animals, I go .45; the .40 would step in if additional factors meant I had to find a compromise between these two, like if I wanted fat and heavy but was restricted to the 9mm frame size. Another might be if I was in an area with mag capacity restrictions and was trying to squeeze the most "firepower" I could into a small carry gun, and the .40 worked but the .45 kept me from hitting the capacity limit.

The biggest "pro" to the .40 is, it lets you squeeze a bigger bullet into the same frame as a 9mm, for times when you need a bigger bullet but not a bigger gun. Not all jobs benefit from a bigger bullet, and then the advantages of the 9mm come into play.

I haven't seen that many GSWs, but the ones that stick out were when I had to chase down a guy shot in the abdomen with a 9mm. He didn't survive long, but was able to run about a block before he crashed.

Another time I happened to be at the ER for another call and went hands on with a guy that got dropped off by his buddy after being shot with a .40. Round went through an arm, and into ribcage. A fragment got his heart and he died on the table. Dude tried to refuse treatment and fought us because of a little weed in his pocket.

Anyway YMMV, but I carry 9mm. I want rounds on target as quickly as possible.

I carried the 40 for my 20 year LE carrier. I think the 40 is maybe a little "deadlier" than the 9 (also the 45 inho) but the 9 is much easier to shoot faster.

My Dept gets into a good amount of OIS and I cannot remember anyone taking a 40 and getting away or continuing to fight afterward. This may be just psychological on the part of the perp giving up. But back when we first got Glock's in 9mm in the 90's, there were lots of stories of guys being shot multiple times and running off.

NO
I believe the move to 9mm is from 2 reasons...
1 - cheaper overall, if your a department that has a small or cut budget, & other needs, it's an fiscal decision.
2 - the need to appeal to the common people that can't shoot well or handle recoil like some woman & smaller sized people. Not everyone that joins the police or needs to use a gun for a job is a gun person.

This. All handguns are relatively poor 'stoppers' regardless of caliber or bullet used. Barring a hit to the CNS, the only way to stop a determined and aggressive BG is shutting down the brain via oxygen deprivation from blood loss. Even a solid hit to the heart can leave 10+ seconds worth of oxygen in the brain, plenty of time for the BG to inflict serious/lethal injury. Shot placement and sufficient penetration are paramount, all else is secondary. All handguns underperform, some underperform worse than others.

With that being said, shoot whatever caliber you're fastest/most accurate with that provides sufficient penetration.

Tomac

OK, here's "real hand" experience, based on 30 years full-time forensic pathology, with hundreds and hundreds of GSW deaths autopsied, many of whom had multiple GSWs.
The good news is that "gel says this" and "yup no difference" is really pretty accurate. Modern service caliber pistol bullets are surprisingly consistent overall, far, far moreso than they were 30 years ago. Yes, there is still some variability between individual bullet expanded diameters and depths of penetration, even from the same magazine into the same person, but the influence of bone (for example) is far less than it used to be.

Whenever comparing cartridges, we must be careful to compare apples to apples as closely as possible. That means looking at dead people, not live people. We constantly preach that a "good hit" is one that produces rapid incapacitation, and that means damaging the CNS or heart/aorta, but we almost always skip over the part where damaging those structures virtually always means they aren't going to live, no matter what anyone does.
Extremity hits and most abdominal wounds with pistol cartridges are therefore simply not relevant for a comparison: critical structures are not being damaged. I'm not negating the fact that the overwhelming majority of incapacitation / stops (whatever term you like) come from non-fatal hits, but those are "psychological stops". By definition, they are not "good hits" - they actually represent a failure on the part of shooter (poor shooting), cartridge (inadequate bullet mass and velocity), and/or bullet (inappropriate design for the task, or simply bullet failure).

When we look at bullet behavior in actual humans, we look at the wound track and the depth of penetration. The evil rumors you've heard about there not being a cup of warm spit's difference in the wound track made by the various service calibers are true. There's also extremely little difference in the wound track made by FMJ v. JHP, until the JHP starts to fragment. Then things get pretty bloody, but the wound track is going to be shallow. TANSTAAFL.

Given all that, it's easy to see that it doesn't really matter what pistol you use to smash the critical structures, and if you miss the critical structures, it also doesn't matter much. The marked advances in bullet technology over the decades since 1986 have primarily resulted in consistent bullets. The trick wasn't getting a bullet to penetrate deeply and expand, the trick was getting every bullet in the box to penetrate deeply and expand.

On another forum, an LAPD firearms instructor said they review reports from shootings from all the agencies in LA County. Shootings involve 9mm, .40 and .45. He said that he had yet to see a shooting where caliber made a difference. A good hit with any of these solved the problem. A bad hit didn’t work out.

Carry what you can shoot best with. In 12 years as a cop I saw a .17 cal pellet rifle kill a 14yo boy with a single shot to the heart, an officer killed by a Ruger p89 firing a 115fmj to the heart, 40 180 gold dot to bad guys head, 380fmj hit carotid in neck, my partner not wearing a vest took a load of 00 buck to the chest at 3 feet and proceeded to put 2 45acp 230gr black talons in the suspect chest doctors saved my partner suspect was DOS. Another officer shot a lady trying to stab him with 2 40sw 180 gold dots one hit to the leg other to pelvis she lived.

From everything I have seen there isn't a ton of difference between a 9mm, 357 sign, 40 and 45 auto.  Maybe small differences bit nothing major you have to step up to 10mm, 357 mag etc to see a big improvement in performance.

They're not equal. The .40 shoots a heavier/larger diameter bullet at the same velocities that the 9mm shoots lighter/smaller diameter bullets. Based entirely on physics, they can't be equal. However, the argument is that the difference between the two is not enough to matter when all of the variables involved in defensive shootings is factored in. Pick the one you shoot the best.

Something that I've brought up before is- there are a number of people on this board that have shot deer or other game animals with service calibers. After following those discussions something that I have heard/picked up on is that generally .45 acp/.357 mag/ 10mm/.40 S&W do better than 9mm.....based on people that have used both. Subjective? Sure, but it's something that's almost unanimous across the board.

To throw in another thought. If you're like me, I spend a lot of time watching gun fights online (YouTube channels like "Active Self Protection" for example). Without actually knowing the stats, I would bet that MOST of the shooting videos we're watching online involves people using 9mm handguns- especially the videos from outside he US. You'll see people get hit and continue to fight. You'll see people get hit and drop instantly. You'll see people get hit, fight just a little bit and then expire. What is the main difference between all of these?

Where on their body they were hit. Shot placement above everything. So while I would argue that 9mm is not equal to .40 S&W, the one you shoot the best is what matters most.

I carry a 9, I'd prefer a 5.56 but it makes my pants too saggy.

I've never seen a GSW.

That said I will always consider a wider, heavier projectile with superior expansion and penetration to be better. .40 does that with reasonable capacity.

What?!?  No one carries the 50AE?!?
Nice wide projectile and good velocities.

My guess is a lot of the difference stems from hollowpoints vs JHP. Many of the shootings where suspects are not immediately physically incapacitated seem to come from less developed countries, where one imagines the duty ammunition is primarily FMJ or older hollowpoints that don't expand most of the time anyway. In these cases suspects are often able to act (though they usually just run away or surrender anyway) even after taking repeated rounds to the chest.

With videos coming from the US and European countries, it usually seems to be a quick dump and it's over. Nevertheless it frequently takes more shots to stop than a lot of people would think; three is optimistic.

It's not enough to hit the vitals, the shots need to do enough damage too. Put a needle through even the heart and they'll be able to walk around fine hours later. That being said, in cases where good ammunition is used and a large number of rounds are expended, post autopsy often seems to reveal that many of the bullets simply didn't hit anything important. In general, failures to stop even after a large number of hits tend to be attributable to poor bullet performance, lack of vital hits, or both (e.g. Miami 1986).

This has been settled:  There is no meaningful terminal performance difference between modern SD ammo calibers.

If you read any of the following words, run away:
- DRT
- Energy Dump
- Ft. Lbs.
- Knock Down Power
- One shot Stop

It hasn't. 40s and 45s do a better job with barriers and stopping fights but if you factor in cost of ammo, qual scores from small people, wear on firearms, and capacity the 9 edges out.

The difference in bullet diameter between 9mm and 40 is 0.044". That is very small.

The 9mm has more capacity and less recoil allowing you to put more shots on target faster.

I would take more shots on target over a slight increase in bullet diameter.

Got any hard evidence to support that assertation? 'Cause if that's true, how do you explain this?: https://www.policeone.com/police-heroes/articles/why-one-cop-carries-145-rounds-of-ammo-on-the-job-clGBbLYpnqqHxwMq/

Tomac

The FBI report explaining the switch back to 9mm does.

I try not to explain outliers because it isn't really productive.

I don't think the .40 or .45 are hammers of Thor. I'm perfectly comfortable carrying 9mm. If I could snap my fingers and turn one of my 1911s into a reliable 9mm one, I would.

Not me personally but I've read on forums people who have used both on duty and prefer the .40.  I don't assign any magical powers to the .40 but to assert that 9mm and .40 are equal is silly, they're not.  The .40 will "fail" if shot placement sucks, but that goes for even rifles. The problem with saying the 9mm isn't as good is that you instantly draw the ire of every 9mm owner out there who have already convinced themselves the 9mm is just as good as anything else.

Shot placement is everything.  With that said most people would be surprised to see the effect, or apparent lack of effect after placing rounds on a person even if there shots find their target perfectly.

Also, if you're hiking in Alaska you might as well throw either of those guns at a grizzly as they won't do anything.  In grizzly country you better be packing a S&W .500 if you want a chance.

Got any hard data to prove the .40 is significantly better than 9mm?

Did he claim it was significantly better?

Read this: https://www.ammoland.com/2018/02/defense-against-bears-with-pistols-97-success-rate-37-incidents-by-caliber/#axzz63qnCTv00

5pins testing of Underwood .40 Hard Cast made me feel a little more comfortable with it as a viable woods gun...

https://www.ar15.com/forums/Handguns/Underwood-9mm-and-40-SandW-Hard-Cast-in-Clear-Ballistics-Gel/20-189427/

That's cool....good for them.  I'd feel very lucky if I were them.

Here's the post I made that had all of his hardcast bullets tested.
Hardcast performance

I don't like using clear gel as a test medium because the results are not the same in living tissue or organic gel but we can compare bullets to different bullets. I think hard cast comparacents are even more accurate since expansion in clear gel is completely different than in organic gel. With hard cast bullets we're just looking at penatration without unrealistic expansion to throw off results.

"to assert that 9mm and .40 are equal is silly, they're not." He sure isn't claiming it's significantly worse, is he?

Tomac

Other than jell tests, there is no "hard data". Too many variables. Marshall and Sanow tried it back in the 90's and were attacked and now considered debunked. Then there was the "Strasbourg" tests where hundreds of goats were shot and the incapacitation of the goat was timed with a stop watch. Light and fast bullets were deemed to be the "best", including the now debunked and heavily ridiculed Glazer and Magsafe loads.

Even if you had access to all police shooting (OIS) data, there would be too much variables. Shooting two identical people in the chest with the same exact load in a 1/2" different spot could give totally different results: one running off while the other dropped dead. Just the human factors such as drug use, determination, mindset are numerous.

I think data of shooting failures would be more informative. Cases where solid body hits were made but the target failed to drop and continued to fight/flee, etc. I'd rather know what has failed personally.

Personally and anecdotally, I have heard more stories of 9mm failing and yet after 20 years as an LEO, carried only the 40, I have not seen or heard of a failure from the 40SW (same with .223 rifles and shotty). This includes conversations close friends in other big agencies that carry the 9.

I'm not saying that the 40 is a better duty load than 9 for everyone. I carry a 9mm most of the time now (retired). I do believe that the 40 is a slightly more consistent "stopper". Maybe it has a sweet spot of bullet weight, velocity, sectional density etc. and capacity.

I agree there is no hard data indicating any caliber/bullet combo that achieves adequate penetration is significantly better than any other, all are relatively poor 'stoppers'. Shot placement and sufficient penetration are paramount, all else is secondary.
Barring a hit to the CNS, the only way to stop a determined and aggressive BG is shutting down the brain due to oxygen deprivation caused by blood loss. Even a solid hit to the heart can leave 10+ seconds worth of oxygen in the brain, plenty of time for the BG to inflict serious/lethal injury. All handguns underperform, some underperform worse than others.
Hence my belief one should shoot the caliber one is most proficient with, whether it be 9mm, .40, .45, etc.

Tomac

Agreed. I've personally seen minor cal (FMJ no less) like .380, 32 etc make "one shot stops" on the street. I don't mean they sat down and waited for help. They died right there. While a co-worker took several hits with a 45 (including on to the face) and ended the perp. You have to hit vitals with a handgun and even then it may take a while if you have a determined/drugged subject. My philosophy is "shots to the body to distract while I angle for a head shot from cover".

Yet, if I had to face an armed and determined attack at close range and I only had 2-3 rounds max, I'd prefer a 40. I prefer it to ANY other service caliber for this role. Going to war, antifa rampage, CCW to the store, etc...9mm all the way.

I mean 40 is more powerful than 9mm, there's no disputing that. You're pushing a bigger and heavier bullet at the same velocity it's going to have more energy on target. However the small increase in lethality usually isn't worth it for most. Actually hitting your target is far more important. And 9mm is much easier to shoot for most. But hey if you can handle a 40 just fine, then go for the extra lethality. Of course most go for 45 or 10mm if recoil is a non-issue for them.

There are places between equal and significantly better. Perhaps marginally better, a little better, etc.

Ultimately, however, it's a distinction without a difference.
As has already been pointed out multiple times in this thread alone (apart from numerous others on the topic), hitting the important structures counts far, far more than what you hit them with. Only good hits count.

But better enough to justify the reduction in capacity & controllability?

Tomac

I don't really disagree. I've actually been pretty impressed with even 9mm fmj overseas.

I have seen a difference on terminal? performance between 9mm and .45 on deer when hitting bone.

Maybe. I know I can shoot my 45 close enough to my 9s to not really notice a difference in splits at the end if a match.

Capacity? We're not laying down suppressive fire here.

My biggest reason to shoot 9s more is cost.

Depends on the barrier.

AZ DPS kept the .40 when everyone else started switching back to 9s because the .40 penetrates auto-glass better.  Especially angled windshields.

This is what I've concluded from my reading.

I carry a 9 typically, but am comfortable with a 380 or 45. Don't own a 40. You can't win them all, and to me the capacity and power of a 9 are plenty. 380 is weak for my taste, but it's better than no gun. The 40 doesn't offer enough extra performance to justify the reduced capacity. The large frames offer the performance, but lose capacity and require the large frame, which for ccw is a negative.

It's what you can justify in your own head. In my head I can't justify carrying a pistol that's larger and heavier with much lower capacity. I want the most rounds I can get, knowing that chances are all bullets are relatively ineffective, and I want to put as many on target as fast as possible. So that leads me to 9.

So usually it's the typical "glock 19" answer. It's the goldilocks pistol to me. If large predatory animals were a concern, I'd probably go for a glock in 10mm. For social applications, I'll keep my g19.

People worry about it too much.

My department has has good performance with 40S&W in our shootings. That being said, we're in the process of switching to 9mm. I'm sure we'll have good performance with that as well. While there is a difference, I believe it to be minor.

Actually the data says they are all actually very good at stopping the attack.  Almost always the person being shot or shot at stops the attack.  It's very rare that the attacker continues to fight after a bullets hits him

Look at different hollow point gel test.  There is not a significant difference in wound channel between 9mm, 40 and 45.  Now compare that to 10mm or 357 mag.  There is a significant difference between the performance of the latter two cartridges compared to the first three.  Wound channel is significantly wider and deeper.