YIKES: 9mm in 40S&W Failure

Double yikes. This shooter is lucky to be alive. Here’s the story: an inexperienced Smith and Wesson M&P owner decided that his .40S&W chambered handgun could also shoot 9mm – without switching barrels. What happens next is cringeworthy; he proceeds to load up a magazine, alternating between the two different caliber rounds.

The first shot, a .40S&W, functions normally, but the second round, a 9mm, is where everything falls off the rails. Whether or not the round actually fires and the spent case follows it into the barrel or the entire unfired round is pushed into the barrel is unclear. Either way, at this point the barrel is obstructed.

The next (and final) shot is a .40S&W that chambers and fires as designed. The bullet strikes the 9mm case in the barrel, causing the resulting damage seen here. Luckily, no one was injured.

YIKES: 40S&W in 9mm

YIKES: 40S&W in 9mm

I go back and forth in thinking whether or not the 9mm round actually fired. On the one hand, the damage makes me think that the .40S&W impacted the primer and caused a secondary explosion inside the barrel. On the other hand, a 9mm case, when fired in a larger diameter barrel, has been known to expand to fit inside the barrel. That bloated casing halfway into the barrel could cause a blockage bad enough to expand a bullet on impact.

YIKES: 40S&W in 9mm

YIKES: 40S&W in 9mm

Though the shooter is unwilling to discuss the incident, I did have the chance to chat briefly with a friend of his who was at the the range that day. He says that his friend, though unharmed, is too embarrassed to discuss the mishap.

Be careful, be observant and ask questions when something doesn’t feel right. And carry a medical ‘blowout kit’ at everybody range session.

Not to add insult to injury, but M&P conversion barrels can be found at online retailers like Brownells.


LE – Science – OSINT.
On a mission to make all of my guns as quiet as possible.
Twitter: @gunboxready
Instagram: @tfb_pete


  • CS

    Well at least he hasn’t tried full sized 10mm Auto yet.

    • Richard

      I imagine that he won’t put that on snapchat.

      • NoNamesOnTheNet

        I have a full size 10mm Auto (G20).

        I run .40 almost exclusively at the range, without any changes to the gun, and I haven’t had even a hiccup.

        I don’t even think it’d be possible to try to run a 10 in a 9/40/357 though. Or if you could, I don’t even think it’d go into battery.

        • Richard

          The cartridge is too long to fit in any of those

  • Hellbilly

    Shame. Obviously this individual sought zero instruction on the proper use of firearms before firing that pistol. He probably didn’t even glance over the manual where it would have said to use only the caliber it was designed for.

    • tinacn

      I hear you. I was once at a rather well-known range in Fairfax, VA and noticed a dim-wit next to me was firing a semiauto that was ejecting “swelled” cases with damaged rims. I picked one up, discovering it was a 380ACP case. The firearm he was shooting was a 9X19 chambered something-or-other. I gently informed him that he was shooting the wrong ammuntition in his gun. He replied that it was “his buddy’s gun and he gave me it and the ammo and told me to shoot it up”, AND PROCEEDED TO CONTINUE FIRING IT! I immediately informed a range officer, who intervened with authority and stopped things. Make you wonder how some people make it to adulthood without getting hit by a truck or some such.

      • CountryBoy

        May of them don’t make it to adulthood. It is often all the better for the rest of us.

        Now, if only the guy’s buddy could have suffered the consequences of education too.

        • Swarf

          Sounds like somebody didn’t want their “buddy” coming home from the range with all their fingers.

  • BattleshipGrey

    Possibly influenced by Demolition Ranch’s video (9mm in .40)? He was at least remotely firing it though and has a bigger budget in case of kaboom.

  • John L.

    The guy is too embarrassed to discuss it … Yet somehow pictures are available from him or his friend?

    Guess he thought it was cool until the universal derision started. One thing I like about the firearms community, stupid stunts are usually regarded as just stupid and not fun / cool / wicked / whatever.

    • 40mmCattleDog
    • noob

      see that last picture? “M@p blew up”? snapchat.

      once you snapchat a friend, you hope they let it go into the bitbucket without saving it.

      only this time, it was too good to not save.

    • AJ187

      I would be too embarrassed to admit I owned a 9mm too. Probably has girlie wrists…

      • SaP ReApEr

        Typical tough guy..

      • Mike Mosley

        Ummm maybe if there was any discussion about a 9mm gun in this article. The gun was a .40….not a 9mm…so maybe not being able to read would be a little more embarrassing lol

        • Daniel

          Mike you cant read the guy had a 9mm round in the 40 cal ahnd gun and fired the 9mm then the last round was a 40 and all hell broke losse heance the talk about a 9mm. U need to take your own adivce

          • Mike Mosley

            Lol wow really? Ok look….slooooow down and actually READ what I said. There is nothing said in the article about a 9mm GUN, only a 9mm ROUND. ???

      • kcshooter

        Congrats, that’s the dumbest comment I’ve seen on the entire internet all week.
        You win. Good work.

  • TVOrZ6dw

    Mmm, so the first 2 rounds did work…

  • Harry’s Holsters

    WOW! I know a guy that fired a 40 through a 45 by accident. When he shot it he knew something was different. Said the gun went from completely reliable to spotty at best.

    • Swarf

      So, not a 1911 then?

      • Harry’s Holsters

        It was a Para Warthog I believe.

  • JannaR

    Some people’s kids. *smdh*

  • Major Tom

    Aye, qué carajo cabrón! How did this seem like a good idea?

  • The prize he won barely seems stupid enough.

  • ExMachina1

    That’s also what can happen by accidently letting a 20ga shotgun shell get into a 12ga gun.

  • Aaron Stewart

    My brother in law accidentally loaded a 9mm in his .40 one day at the range. The round fired but the case cracked and expanded in the barrel. I believe it would’ve fired another round if he hadn’t realized his mistake. Perhaps that happened here?

    • Nashvone

      Except this was no accident.

  • Pete Sheppard

    Darwin is patient…

  • Drew Coleman

    I’ve seen people do something like this on accident – a former coworker loaded a .40 S&W cartridge in his XD-45. Luckily it was just a stuck case with no further damage.

    But to do it on purpose? Idiot.

    • BillC

      and purposely staggering different calibers.

    • a_b704

      I put all my rounds in ammo boxes. Different boxes, for different calibers 😉

      • Nashvone

        Let me guess. You also sort them by shelves in your safe? Oh wait, that’s me.

        • a_b704

          Unfortunately, no – need more safe. Guns are in safe, ammo is on the heavy duty shelf unit beside the safe. The internet tells me to keep the ammo out of the gun safe, in case of fire. Of course, the internet also tells me Taurus is better than Hi-Point, so the internet can be wrong 😉

          • Nashvone

            I keep my ammo in a separate safe. Not because I’m worried about fire but because of the money invested in it.

          • David Christensen

            Not better – just LIGHTER!

          • a_b704

            No kidding. I just broke open a thousand round case of Malaysian manufacture .308FMJ I purchased in the 1980’s – headstamp dated 1985. I paid $134 at a gun show then. I bet it would be hard to find a thousand rounds of 308 now for twice that.

      • David Christensen

        All my AR-15s that shoot 5.56 are BLACK. Other calibers are different colors. .300 BLK = FDE, .458 SOCOM = Burnt Bronze,. 6.5 Grendel = Kryptic Camo in browns. All gun ejection doors and mags are WELL MARKED!

        • a_b704

          Until recently, I had not purchased guns since the 80’s – my AR is from around 1982. I hadn’t even heard of those other calibers.

          I want to build a 9mm AR that takes Glock mags though. I think. But I also heard of an upper that simply takes the lower of the Glock, much cheaper

  • stephen

    During a match I used my Glock 23 (.40 caliber). It was the first round so when the first shot went off, it fired but did not cycle. I ended up racking the slide, fired again = same result. The third time I stopped, cleared the firearm. I went to check what was going on and found out I had 9mm rounds.

    What ended up was that my kid was firing a 9mm a day earlier and when we were cleaning up she accidentally put some 9mm rounds in the .40 container. Regardless I should have been paying more attention when I was loading. Lesson learned – I check every round I load.

    The good thing was that the shots I did fire hit the A zone and the firearm had no damage. The rest of the match was all good.


    • Bierstadt54

      That moment when you realize you just did (and got away with doing) something that could have ended very, very badly.

    • David Christensen

      If something (discharge) doesn’t “feel” right, carry a wooden dowel and check the chamber and barrel. I had a round with what I suspect was not enough powder. It stuck half way down the barrel. Another round headed out would have been a real problem!

      • Swarf

        Chopsticks are wonderful tools. I carry a set in my range bags and all my work tool bags as well. They make good non-marring pokey things, and are great non-conductive probes for breaker panels, control boxes and the like.

        • Warchild_70

          Now that’s a great idea Swarf. I’m going to get them at my favorite Kings Wok next time I visit. Thanks from an old school Engineer.

    • Oldawg

      I did the same thing with a 9mm gun loaded with .380 ammo. I was shooting both that day and just loaded from the wrong box. Same results that you had. Of course 9x19mm and .380 are the same diameter, just not enough energy to cycle the action.

  • J.T.

    Play stupid games, win stupid prizes.

  • Phillip Cooper

    Darwin award nominee, most definitely.
    Stupid should be painful. I hope this was.

    • Joshua

      he, and his junk, are still alive, Darwin award is for removing oneself from the gene pool. there is still a chance that this one might propagate

  • TheNotoriousIUD

    The day I need a blow out kit at the range is the day I look for a new range.

    • JamesG3

      It’s why I only shoot with known quantities. If I pull up to the range and don’t know you, I’m not even getting out of the truck. Too many inexplicable holes in the roof over the range tables to take the gamble.

      • TheNotoriousIUD

        Thats scary, and another reason I prefer outdoor ranges.

        • Andrew Miller

          Indoor ranges don’t have a monopoly on roof holes.

        • Evan

          I shoot exclusively at outdoor ranges, and can often see the marks where bullets clearly hit the benches. Some people are just idiots. I’ve never seen anyone doing anything that stupid, but I guess I’ve just been lucky.

      • Nashvone

        I live in a city with a million residents and MAYBE a dozen ranges. If I wouldn’t go in with someone I don’t know I might as well get rid of my guns. However, I’ll leave in a hurry if someone seems to be doing something unsafe.

        • Swarf

          I live in a city with four times as many people and half as many ranges. The idea of being sniffy about whether I’m best buds with every person there is laughable.

        • SaP ReApEr

          Or get a range officer to intercept them you meant?

      • CountryBoy

        Had two young guys in a pickup truck pull up to the rural outdoor range while my sons and I were shooting clay targets – skeet – swinging to lead the clays, etc. We’d been there about an hour and were the only ones there.

        These two guys get out and proceed to walk downrange right next to the lane we were in. No “Hey!” or waving, just heading down to the 100m target to nail a bullseye up. When the first guy headed that direction I called “CEASE FIRE!” for our group, and watched in awe as Bubba and Beedle casually walked right across where we’d been hitting clays. I couldn’t believe it.

        When they returned I asked them if they had a first aid kit, and the one guy opened his cooler and offered me a beer.

        Needless to say, I said no, thanked them and we left.

        The reason gun sports are so safe is because they CAN be so dangerous, but they’re only safe when people take care to keep them that way. These two were trying to get in the Darwin Awards, but they’ll have to do it without my involvement. I still have no idea what they were thinking, or IF they were thinking.

    • Hoplopfheil

      My localest range has bullet proof steel panels between each booth.

      I still get nervous every time somebody carries their gun around behind the booths though.

      Sometimes when a dangerous person is flailing around with their gun, I’ll take a walk to the back counter and spend a few minutes loading magazines or playing with my phone.

      Shooting indoors sucks.

      • a_b704

        Just look at the walls and ceiling in most ranges. It gives you pause.

      • David Christensen

        If our range master caught someone walking with an uncased weapon behind the booths, he will be stopped PRONTO! We can’t even transfer uncased guns BETWEEN booths. Safety first means not having to explain stupid.

      • Billy Jack

        I’m worried about nuts, morons and thieves at outdoor state park ranges. I’ve been lucky enough to not have seen any of those but I’m always on the lookout for them. I’ve heard too many horror stories to forget the risk.

    • Blake

      Uh you do know accidents are called accidents because they’re not intentional and can pretty much happen anywhere at any time? Ricochets, blown barrels (even with the correct caliber), etc. can all happen any time you’re around guns and it’s always smart to be prepared regardless of how safe you’re being.

      • Kafir1911

        Most car crashes are called “accidents” when in fact carelessness and inattention is the root cause of the crash.

    • Jerry Duchaine


      • Swarf


        • Jerry Duchaine

          Sorry messed up. If you look above you should see my reply to Notorious kid regarding the need of keeping a basic medical blow out kit or IFAK with your range gear just in case as his comment regarding he would find a new range of he needs to carry a kit which I feel is a poor statement personally because bad things can happen anytime anywhere

          • Swarf

            No worries, I just thought maybe it was a code I didn’t know about.

    • Jerry Duchaine

      Emt1489 I might ask you to reconsider your post about not needing a blow out kit at your range. Accidents happen to even the best of us and malfunctions can occur. And as you are standing or lying there bleeding out you will wish that you or someone did bring a kit to help you. I have seen it and treated it I am a public safety professional and a Med kit is a permanent fixture in my home car and range bag. Think about it. Could save you a friend or a loved one

    • Libertarian in 2016

      I carry a blowout kit in the car most of the time and have been taking one to the range for 20 years. Haven’t had any major incidents, but it’s good for the minor cuts and scrapes, too.
      In 1995, I was on the range when a task force officer managed to shoot himself in the leg with his brand-new, department-issued Glock 23. He was sure glad we had a med-bag.
      Accidents/negligence/stupid happens.

    • 1911a145acp

      You SHOULD have a GSW /blow out kit/ 1st Aid Kit accessible everyday. Especially so, if you carry, like to shoot or interact with firearms or possibly encounter bad guys. I have had a large trauma /GSW bag in my vehicle(s) for 30 years. Had to use it on a fellow on our range who shot himself in the foot w/ a 1911. SH*T happens……

  • Joel

    “There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.”
    – Will Rogers.

  • Karl

    I would be embarrassed to discuss this as well . This is just total incompentence. One momentary lapse of attention can be deadly.

  • Brick

    Wait, was this on purpose or was it an accident? Maybe he loaded a 9mm cartridge in the middle of loading .40 and didn’t notice?

  • DIR911911 .

    sounds like the boom knocked sense into hum. silence is golden when trying to put a huge screw up behind you.

  • Sam

    I worked at a range for a couple years and saw different calibers fired out of the wrong guns. I’ve never seen anything remotely like this.

    What I’ve seen the most of is 9mm will shoot out of a .40, and sometimes the extractor will even crab the casing and cycle. Usually you’ll just end up with a mushroomed-out 9mm casing stuck in your chamber.

  • Did he accidentally load a 9mm cartridge into the magazine?

    • Joshua

      no, he did it purposefully, several of them.

  • Sianmink

    The 9mm primer looks intact. Likely when the .40 round struck it, it had a spontaneous uncontrolled disassembly.
    How in the heck did he end up with 9mm and .40 loaded in the same magazine, alternating? Something is really really fishy here.

    • Joshua

      from the sounds of it he loaded it that way intentionally to test a theory

      • Sianmink

        Well, I hope to see his thesis published in the journals soon.

        • Richard

          Considering that he will be mocked like crazy, probably not.

  • iksnilol

    .40 Small and Weak: so weak that even a piddly 9mm is enough to stop it.

    • efred1

      Yes, the .40 Small & Weak is so small & weak, that it has more power than the smaller and less potent 9mm.

      • iksnilol

        Then how does a 9mm destroy a .40 S&W but not vice versa?

        Checkmate atheists.

        Also, in all seriousness, if you check the energy and performance figures you’ll actually see no ballistic difference between 9mm and .40 Small&Weak

        • efred1

          It’s simple math/common sense: A .40 S&W, being 10mm, is 1mm larger than a 9mm, and thus it will not fit in the chamber of a 9mm.

          Even though there may be no ballistic difference between the two, from FBI shooting incident reports, statistically the .40 S&W is more lethal; its larger, heavier bullet penetrates hardened objects better than the 9mm, and is considered a good compromise between a 9mm and a .45 ACP.

          • iksnilol

            Then why is everyone moving away from the .40 s&w?

          • efred1

            I believe it’s because it has a report not much louder than a .22, and recoil that corresponds. And they decided to not learn from history.

            The nines are fun to shoot, have a (relatively) low report, and followup shots are easier due to the low recoil. But they statistically require more rounds per target.

          • iksnilol

            The data on 9mm shootings is skewed because most folks were taught to doubletap.

          • efred1

            If that’s true, then why don’t the .40’s doubletap as well? Or the .45’s?

          • iksnilol

            Because the snappy/long recoil of those cartridges (respectively) makes doubletaps difficult?

          • efred1

            Normally, because the first shot did the job.

          • iksnilol

            Look at this for a moment: http://www.buckeyefirearms.org/alternate-look-handgun-stopping-power

            That is data compiled from thousands of shootings. Both 9mm, 40 Small&Weak and .45 ACP on average required more than two shots to stop the target. So you can let the “mah stopping powuh” and “one shot stop” myths die already.

          • efred1

            The FBI’s shooting stastics are much more complete, and thus, more accurate and reliable. This guy gleans only from what he can find in news reports, not the actual reports sent from the pathologists and doctors to the FBI.

          • iksnilol

            Feds are going to be saying the same thing I did. Otherwise they’d all be carring .50 AEs, 10mm Auto and .44 mags.

          • Billy Jack

            Feds are saying what you both are to a certain extent. Basically, everybody suck when things get hairy and you’re better off with more chances with a projectile that is equal to or better than most .40/.45 and that most shooters do better & faster with. That projectile is the 9mm.

          • iksnilol

            Yup, federales moved back to 9mm when they found out that a 9mm hollowpoint is just as damaging as a .45 acp hollowpoint. That and stopping power is a myth.

            But y’know, you can plug two of them into somebody in the time span of shooting one .45.

          • buzzman1

            You have that screwed up. The 9mm hollowpoint is the same as a .45 ball round. It was also comparing the 9mm to an army .45 ACP that travels at 830 fps which is about 100 fps slower than an average commercial off the shelf round.

          • iksnilol

            No, they compared 9mm hp to .45 hp. I got the gel pictures if you want. Difference was marginal at best.

          • buzzman1

            The stock testing commonly cited was a comparison of the 2 rounds in testing done by the army at Aberdeen Proving Ground. The 9mm HP outperformed the 45 FMJ ball rounds. God bless you if you prefer the 9mm. Everyone has their preferred caliber.

          • iksnilol


            This is the test I’m refering to. Sure, .45 opens up a bit more around the 15 cm mark but is overall a negligible difference.

          • buzzman1

            Thanks for the chart. Penetration has never been an issue with 9mm however this chart shows that the wound cavity of a 9mm JHP is half of that of .45 and that is the key.

            Modern ammo is really upping the lethality of all calibers of weapons. Go to You tube and check out the gel tests for Underwood ammunition. They even make a .380 round that performs as well as a 9mm.

            Bottom line is guns/calibers are like women, neckties and bourbon to guys. Everyone has their preferred type so and long as you can shoot well with it and its 9mm or larger then go forth and be happy.

          • cageordie

            This is such BS. Idiots read a report they don’t understand and conclude something which isn’t true. If caliber and energy make no difference then a 177 airgun should be as effective as a 50bmg. Which is obviously garbage. If you are able to understand that this is not a binary universe, that effects vary on a sliding scale, then there’s no quantization of affect, and hence caliber and energy do matter. Switching to the best caliber for bad shooters doesn’t give the best result for a good shooter. We can also see from the statistics that police don’t stop at double tap, that’s for paper warriors. Police shoot until they run out of bullets, even when their target has fallen to the ground. Anyone who has hunted can tell you there’s a major difference in affect between calibers. A 22LR can occasionally kill a moose, a 308 will do it with one shot a lot more often and Alaskan guides carry large caliber backup rifles because making a bigger hole has always worked for them.

          • iksnilol

            Yeah, before writing your nonsense did you consider that the difference between 9mm and .45 acp is much smaller than the difference between .22 lr and .50bmg?

            Just curious is all.

          • cageordie

            I applaud your understanding of the difference between big and small. So you’ll no doubt be able to stretch your understanding to the difference between a typical 115 grain 9mm round and a typical 230gr 45 round (11.2mm). In your ignorance you are fixated on the small difference in diameter and are ignoring the huge difference in volume and mass. Naturally you picked an old round with similar energy instead of a 10mm or even a 357 Sig. In the game of chance you play when shooting or being shot why would you roll a smaller dice if you have the choice? The whole argument has always been intellectually bankrupt, but one idiot writer says it on clowns follow him for the next fifty years. There was that poor baby who found the 10mm too hard on his ickle soft hand, same guy who had no trouble with a 357 magnum with pretty much the same energy and recoil, but he caused generations of people with no sense to ignore the cartridge and it is only now gaining the popularity it deserved. 10mm isn’t for everyone, just people who know what they are doing. Meanwhile the ‘experts’ who never shoot will buy their wife a 2″ 357 titanium revolver with pretty little rosewood handles, about the most unpleasant thing I have ever shot. In the end I couldn’t care less what you think. You are unlikely to be on my side in a shooting war, so believe whatever you want.

          • iksnilol

            What? I “ignored” the difference in mass because it is compensated mostly by velocity difference.

            But, very important point incoming:

            I am definitely too sober for this so I am not gonna bother, you, oh great person with no credentials knows better than the US military, FBI and DEA (groups which I dare say have more experience than you in shooting things). So what I am going to do is, hit “Post”, then press the “x” in the upper right corner and enjoy my tea. So have a nice day I presume (it’s evening where I am at)?

          • Billy Jack

            From the FBI in 2014 courtesy of TFB & LooseRounds & my Evernote account. You’re both right.
            (And you guys just help re-convince myself to go 9mm again after forgetting this argument the FBI made)

            “May 6, 2014
            FBI Training Division: FBI Academy, Quantico, VA

            Executive Summary of Justification for Law Enforcement Partners

            Caliber debates have existed in law enforcement for decades

            Most of what is “common knowledge” with ammunition and its effects on the human target are rooted in myth and folklore

            Projectiles are what ultimately wound our adversaries and the projectile needs to be the basis for the discussion on what “caliber” is best

            In all the major law enforcement calibers there exist projectiles which have a high likelihood of failing LEO’s in a shooting incident and there are projectiles which have a high ting incident likelihood of succeeding for LEO’s in a shooting incident

            Handgun stopping power is simply a myth

            The single most important factor in effectively wounding a human target is to have penetration to a scientifically valid depth (FBI uses 12” – 18”)

            LEO’s miss between 70 – 80 percent of the shots fired during a shooting incident

            Contemporary projectiles (since 2007) have dramatically increased the terminal effectiveness of many premium line law enforcement projectiles (emphasis on the 9mm Luger offerings)

            9mm Luger now offers select projectiles which are, under identical testing conditions, I outperforming most of the premium line .40 S&W and .45 Auto projectiles tested by the FBI

            9mm Luger offers higher magazine capacities, less recoil, lower cost (both in ammunition and wear on the weapons) and higher functional reliability rates (in FBI weapons)

            The majority of FBI shooters are both FASTER in shot strings fired and more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W (similar sized weapons)

            There is little to no noticeable difference in the wound tracks between premium line law Auto enforcement projectiles from 9mm Luger through the .45 Auto

            Given contemporary bullet construction, LEO’s can field (with proper bullet selection) 9mm Lugers with all of the terminal performance potential of any other law enforcement pistol caliber with none of the disadvantages present with the “larger” calibers

          • buzzman1

            9mil ammo is cheaper and easier to get. Also high capacity with a smaller cross section.

        • Aardvark

          A larger diameter bullet is going to leave a larger diameter hole, which is going to lead to faster bleed out.

          • iksnilol

            A larger diameter bullet doesn’t necesarily lead to a bigger hole. Look at the tip of a .45 and 9mm. You’ll see that it tapers down towards the tip. You might also notice both pistol bullets are pretty round.

            It’ll push flesh aside more than pierce it.

  • Evan

    Hold my beer and watch this!

  • Jeff Smith
  • Sunshine_Shooter

    The entire 9mm cartridge went into the barrel. I don’t know why, not even really sure how, but that’s what happened.

    The fact that the guy doesn’t know the difference between “&” and “@” doesn’t make me give him the benefit of the doubt. How can he be expected to know how to use guns when he can’t even use a keyboard?

  • Jeremy

    I did the same thing with a .40 MP5. Got a 9mm somewhere in the mag. The whole 9mm round went into the chamber and did not fire. I chambered a 40 behind it and then stacked about 7 or 8 40’s behind a 9mm case that went off and obstructed the barrel. The barrel looked really egged, but did not split. The smoke pouring from the gun made me stop and inspect.

    • Nashvone

      Higher quality German steel?

  • Cal S.

    But it was on this survival blog…

    The cause of 90% of the gun guys’ problems.

  • Porty1119

    9/40 burst?

  • Sasquatch
  • Larueminati

    I’ve shot a 9mm through my USP compact .40S&W, didn’t even know that I did until I went to clean the brass and saw a 9mm case expanded to the size of the 40 chamber. It cycled because I had no malfunctions. I could see how this failure could happen with a barrel obstruction though.

    I’ve read that supposedly one of HK’s torture tests is clearing a squibb with a live round, not saying i’d try it but it should be able to handle it.

    • kcshooter

      No. No, no, no. No.

  • scaatylobo

    Been there,done that.
    I was shooting 2 Springfield DXS’s.
    One was 45,and I also had a box of .40 S&W’s for my carry Glock in the bag.
    Fired the .40 in the .45 barrel —- and NO damage !.
    Lucky me and REALLY GOOD LESSON learned.

  • pithy

    When I was young and stupid, I was shooting my service M&P40 and a 4507 (I think) Smith that my uncle had lent me to try out for possible purchase. I had 40 and 45 all together and was loading and shooting to my hearts content. I started shooting the 45 and when I fired, I heard a weird sound–a sound unlike the standard gun firing. I checked the chamber and lo and behold, my dumb young self had fired a 40 through a 45. The case expanded, the bullet left, and I learned a valuable, lifelong lesson:

  • Sulaco5

    Saw a 9mm in a .40 Glock once. Strange sound but no damage when it went off…case was split slightly.

  • durabo


  • a_b704

    Well, Smith does have a lifetime warranty. Not sure if it covers ‘dumbass with a gun’ though.

  • DanGoodShot

    By looking at the pic it doesn’t look like the 9 fired. I’m not seeing any primer strike. As far as this incident goes…. wow… just wow. I don’t think I’d want to talk to anyone about it either if that was me. Hey, this gives me an idea. You guys should start a new segment, like POTD, but call it DOTD(dope of the day). Lol

  • jerry young

    I would hope this was done as a demonstration to show what would happen if you tried to shoot the wrong ammo and done in a vise not someone holding the gun, if not this guy is dumb as a box of rocks make that a box of rocks has more brains than this guy! this type of thing is exactly why I always comment on how dumb it is to do things like see what happens when you stick a carrot in the barrel of a 12 gauge and yes that one was done too, one of the big firearm safety rules know what ammo your gun uses and make sure you use only that ammo, it’s right in the manual that comes with your gun and is so important it’s stamped somewhere on the gun itself usually the barrel or slide.

  • Kafir1911

    An Obamian or Clintonista in the making????

  • tinacn

    Back in the ’80s I remember reading an article where a research team took several bolt action rifles, hammered unfired bullets into the barrels, and then fired them in a test chamber to see the effects. None of the rifles burst open, but they were damaged. One or two same model rifles were given the unfired bullet treatment, and a few grains of cannister powder (I forget exactly which one or exactly how much) were poured into the barrel through the chamber end (putting the gunpowder behind the plugged area). The rifles were then loaded and fired in the test chamber. The results were catastrophic, with the barrels bursting, chambers rupturing, and one bolt flying backwards out of the receiver. This led the researchers the conclude that under such extreme conditions (known as an adiabatic compression in chemistry or physics parlance) caused the normally “progressive burning” powder to actually detonate in an explosion. Some few did not believe this mechanism to be the case, but there was obviously SOMETHING abnormal going on. Perhaps this is a similar situation, with the unburned powder in the 9mm cartridge “exploding” under extreme compression.

  • Thomas

    I once had a relative I didn’t care for ( former bro in law) shoot himself in his own leg while dicking around with his glock. Pulled it out of the holster, loaded mag with one round in the chamber too…….fingers magoo gets one in the thigh as he pulls his gun out of his holster. His new nickname was Barnabus A Fife and he never did get the cop job. This was at the police training school.

  • M

    Too stupid to own a gun. I hope it was his only one, otherwise he tries a 300 Blackout in his AR-15 chambered for 5.56 ? At least nobody was hurt, thankfully.

  • Cea

    I hope Darwin gets this guy before he ends up next to me on the range!

  • Tony Miller

    Everybody makes mistakes just some are WAY bigger than others.

    • CountryBoy

      “Everybody makes mistakes, some just make more shrapnel than others”

  • BigFED

    I had nearly the identical situation happen a couple of years ago on our indoor range. A retired Deputy Sheriff brought along his teen age son to introduce him to shooting. After we went over the ranger rules and assigned him to a lane, he asked for a box in 9m/m ammo. He paid up and went out to the range. After hearing a couple of shots, the son came in and told me they were having “an issue” with their pistol functioning. I went out and found the he was trying to use the 9 m/m ammo in his Glock 22 (.40SW caliber). After the “aw chit” moment and his explanation that he also has a Glock 17 and he thought that is what he was using. Anyway, I rounded up all the 9 m/m ammo in sight and placed it BACK in the ORIGINAL 9 m/m box. He then bought a box of .40SW ammo and was getting ready to resume shooting when I went back to the sales counter. After a few shots, that son came back out and said they were having another problem! I went out and found their pistol had the slide jammed back about 3/4 inch out of battery. I dropped the magazine and it was loaded with .40SW and I could see from the slightly open breech the remains of a .40SW case. After a careful look down the barrel (not dangerous since the breech was blocked/locked and the pistol couldn’t possibly be fired), I saw to the distinct nose of a 9 m/m round. Apparently, the man had discovered that he had in his pants pocket, a full mag of 9 m/m rounds that he originally intended to use. He had removed the rounds from the mag, but apparently got his hands mixed up and he loaded one of those 9 m/m rounds in the mag he had loaded to resume shooting.

    First few rounds were .40SW and then that 9 m/m round WHICH DID NOT fire when he pulled the trigger so he cycled the slide. The 9 m/m round did not extract and was pushed up the barrel by the .40SW round coming out of the mag. So when they pulled the trigger, BANG!!!

    The pistol, to Glock’s credit, was “recoverable”. I took it to my workbench where I was able to, with a leather mallet, drive the slide forward. It had a little free play, and I was able to remove the slide in the “normal” manner. A couple of raps with that leather mallet and I got the barrel out of the slide. It has split about a third of the way, just about where the 9 m/m would be with a .40SW behind it. Since the 9 m/m round was loose in the barrel, full pressure was not developed, preventing a MORE catastrophic failure. I advised him that I would NOT replace the barrel even though that was the only OBVIOUS part the needed replacement! As a Glock Armorer, I would not rep[lace or certify the pistol after repairs. He would have to send the pistol to Glock. Needless to say, he was very embarrassed and left the range, AFAIK, never to return.

    • CountryBoy

      Had a similar situation with a friend whose Bersa Thunder reacted quite logically to what was probably a double-charged handload. A buddy of his had given him some “free” ammo he’d loaded up, and one was a bit more feisty than the rest, splitting the barrel and driving the slide back. Bersa was able to repair it, but it cost almost as much as a new one.

  • Mike Lashewitz

    He did in on purpose . . . . .


  • Aimon Bustardo

    And the Darwin award goes to….

    • Swarf

      Nobody. He lived.

      • Aimon Bustardo

        True…. Consolation prize: Being forever ridiculed on the internet. 😉

  • 1911a145acp

    Possible scenario sequence explanation. 1st 40 S&W round fires normally, ejects and loads 9mm FMJ round into the firing chamber, pulls trigger 9mm fires,bullet exits barrel, case fails to extract, but slide moves slightly to rear, fired 9mm case is dislodged from extractor by rising 40 S&W cartridge from magazine, shooter misses the fact that the 9mm case has not ejected, pulls trigger gets a click, racks slide, next 40 S&W round pushed 9mm fired case into chamber and barrel throat far enough for the M&P to go into battery and next trigger pull results in explosion from over-pressure due to bore obstruction. Alternatively, shooter hand cycles 9mm round into chamber, 9mm cartridge slip out from hook goes deep into chamber. Shooter pulls trigger, gets click, racks slide and chambers 180 grn truncated cone 40 S&W FMJ flat-nose bullet that pushes live 9mm into barrel throat and KA-BOOM

  • Opus 0321

    Somebody, anybody, PLEASE take the firearms away from this Fool before he kills someone! This was not accidental, or carelessness, this was pure deliberate Moronic Idiocy….In the first degree!!

  • HR Pufnstuf

    Had another officer sell me a ,380 really, really cheap, saying it “jammed” all the time. Manufacturer had a good reputation of quality, and fixing problems when they arose, so I bought it, figuring I could send it back, get it repaired, and still have a good investment. The officer also gave me 4 boxes of ammo with the gun: 2 boxes of .380, 2 boxes of 9mm. Hmmm….

    Of course, I’ve shot nothing but .380 in it, and it’s been flawless.

  • Franco Eldorado

    I’m not buying this. I did this once a 9mm got mixed up in my box of 40. It went off and barely made a noise. Split the case but no harm to the gun. I’m betting the 9mm squibbed in the barrel and a 40 behind it

    • Markbo

      Did you read the story??? That is exactly what they said happened.

  • Jim

    It the government ever requires an IQ test for gun and drivers licenses, there will be a lot of unarmed pedestrians walking around looking for something stupid to do.

  • jay

    He should be embarrassed. And harassed for his stupidity. He didn’t just put his life in danger.

  • BigFED

    In the more than 30 years our indoor range has been open, we have NEVER had a GSW, serious or otherwise. We have had cases where a person was bitten by the slide cycling, hit by a fragment of a bullet or a hot case down the shirt, but no one directly injured by a fired round. That includes some fairly major KABOOMS. We did have one person commit suicide not long after we opened in the mid 1980’s. Of course, there is tomorrow!

  • AK

    If the 9mm would have fired, it would have bulged the case and likely prevented chambering of the next round (if not extracted). Looks like the 9mm didn’t fire, because the primer was off-center due to the smaller circumference of the round, got pushed forward by the firing pin off the extractor, was pushed into the barrel by the tip of the .40 that followed, perhaps also pusing the .40 bullet in and compressing the charge (an overpressure risk by itself). Boom.

  • JohnnyCuredents

    This proves the futility of background checks. They don’t catch damned fools who have no business being anywhere near guns of any caliber.

  • buzzman1

    I remember the days when people used to swear the AK rounds and M-16 rounds were interchangeable.

  • CavScout

    The way this article is written… It could have beena single round of 9mm mixed into .40S&W ammo, loaded, and during some quicker shooting you’d be lucky to stop in time for the second shot. Controlled pairs, let’s say. Point is, COULD HAPPEN EASILY.

    • kcshooter

      No, it couldn’t happen easily. You have to be a moron.

      Ok, if you’re a moron, it could happen easily.

  • Don Mei

    The title of this article is misleading. Shooting a 9mm (typically held against the firing pin by the extractor) in a gun chambered for .40 S&W is perfectly safe.

    Shooting a gun with an obstructed barrel is not.

    I’m not saying its something everyone should go out and do. But in a pinch, at arms length distance this can be done safely if one round is inserted at a time and you confirm the brass has in fact ejected and not pushed up into the barrel.