FN Five-Seven KABOOM

Over at the Kifaru forum, “Fairchase” wrote that his FN Five-Seven fired a round out of battery, blowing it up and doing severe damage to his hand and thumb.

Last week my FN Five-Seven blew up causing severe damage to my left hand (I am right handed). There are 6-8 pieces of shrapnel deep in my thumb and palm area which severed the nerves to my thumb and a portion of my palm. Surgery is required in an attempt to repair the hand by harvesting tissue from my leg. Wish me luck.

The “explosion” occurred on the last round of a 30 round mag loaded with the factory 40gr v-max stuff. On this particular day I only had three loaded magazines (70 rounds total) with me for the Five-Seven but had several other handguns to shoot after the Five-Seven. I began with a 20 round mag loaded with hand loads, then a 20 round mag loaded with factory ammo and finished with the 30 round mag with factory ammo. It was the very last round of 5.7×28 in my immediate possession that ruined my day ……. and a whole lot more!!

I have fired (600-700 rounds) both factory and hand loads through the pistol with zero issues since purchasing new in 2/2011. There are reports of the Five-Seven firing out of battery (OOB) which appears to be the case here but I am no weapons forensics expert. I am not a novice to shooting, handguns or reloading and have 20+ years of extensive experience with shooting and reloading.

I have been completely straightforward with FNH (i.e. Browning) so will now wait and see how they respond.

I have a lot of sympathy for Fairchase, but I think its more than likely that it was a handload that caused the kaboom. I would never recommend reloading the 5.7mm FN for use in pistols. The margin for error on a high-pressure and bottlenecked pistol round is a lot less than on an old “boring” cartridge like the the 9mm Luger. The maximum pressure of the FN 5.7×28mm is 50,040 psi vs. 34,084 psi for the 9mm Luger/Parabellum and 35,000 psi for the .40 S&W.

Shooting Times once published an article about reloading the FN 5.7×28mm (since taken down, maybe for liability reasons). They listed a number of caveats for any would-be reloaders …

There are a few things to keep in mind:

  • Using reloaded ammunition in PS90 and Five-seveN firearms voids any warranty and any liability of FNH USA. By choosing to reload, you accept full responsibility.

  • Because of its tiny case capacity, start at the listed minimums and work your way up in 0.1 grain increments.

  • Published load data varies greatly, so err on the conservative side. The min. and max. loads in the Western Powders manual are significantly higher than those listed in the new Lyman Reloading Handbook 49th Edition, which is what I used.

  • The 5.7×28 is very sensitive; adhere strictly to the loading data and COL guidelines.

  • Stick with flatbase bullets and Small Rifle primers. If you use Small Pistol primers, expect decreased performance.

  • Excessive muzzle blast and flash are to be expected with this cartridge.

  • FN- and Fiocchi-made ammunition both employ military-style, staked-in primers. You must ream the staking residue from the primer pocket before reloading.

  • Beware of hotrodding the 5.7×28. Though the 1:9-inch twist rate of the FNH USA guns might tempt a handloader to load heavy bullets, I highly recommend projectiles of 40 grains or less. Too-high pressures can be a real safety concern with the straight blowback PS90 and the delayed-blowback Five-seveN pistol.

The maximum average pressure (MAP) for the 5.7×28 is 50,040 psi.

[ Many thanks to John for emailing us the link. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Munkfish

    This is a very familiar story, I’ve seen a few posts like this over at FiveseveNForum over the years. I think one guy even got FN to replace his gun after he blew it up on reloads. I’ve got several hundred cases of 5.7 saved up for when I decide to try and reload it. I’ll be waiting until I have more reloading experience/better equipment, and I’ll probably only shoot it out of the PS90.

    • Chucky

      I remember that and was a good read too. While FN did cover for the guys loss, they did stress how finicky it was to handload the 5.7 that they don’t recommend it at all which was ultimately the cause of the entire incident. It’s true that the 5.7 can fire OOB, meaning to say the hammer can fall even if the slide hasn’t completely seated a round in the chamber yet leaving a part of the case unsupported. But the guys at FN, on extensive testing found that there was nearly no way the gun would do that under normal operation. They tried to replicate the kaboom incident that happened some 3-4 years ago and it wasn’t a case of OOB. The handload was beyond specification and what happened was the slide gets pushed back too early when there’s still critical pressure in the chamber and blows out the partially extracted case.

      • g in Michigan

        It’s been a while since I read this thread. I rarely carry my five seven and rarely shoot it. I usually shoot a 22 cal gun to save on ammo. The five seven that I have may be a little dry, meaning not lubricated as well as it should be. Also from time to time lint may get into the slide area from Mexican carry. I don’t Mexican carry with it while a bullet is chambered. And Mexican carry is done when I have a different gun as my primary, so no round is chambered. In other words, I’d never carry it Mexican carry with a round in the chamber.

        My point is I haven’t recently cleaned it. My normal gun is an XD. The XD is a nine sub-compact, which is well broken in. The XD has a heavy metal slide and a nice seemingly stiff spring for the slide. My five seven has a fairly stiff factory spring and I’d say it’s not even well broken in with maybe 150 shots fired through it. I sometimes chamber a round kind of silently at home in the XD. This involves not releasing the slide and letting it fly forward. The XD being well broken in and having a heavy slide will always allow the round to be fully seated.

        Sometimes I don’t pull back and let the slide go back as fast as it can by a quick release of the slide on the five seven. In an attempt to allow the gun to chamber the round a little more quietly than if I just let the slide return very abruptly. I think this is from a thought process of how quiet could I chamber a round in the night if someone broke in and was in my house. In other words it’s a bad habit from a quiet chamber drill which always works with my XD by the way.

        So once in a while I quietly chamber a round in the five seven. But looking at the slide, the slide isn’t fully pushed forward. And I have to push it forward fully hearing the chamber click fully into place.

        I cycled four rounds using this silent chamber technique through the gun and each time the gun didn’t have the slide seat properly. I don’t know if the gun would fire with the slide almost fully seated, and I’m sure not going to fire it that way to see if it would fire and kaboom. This is with factory blue tipped ammo which is all that this gun has seen. No reloads. So I’m thinking, well maybe it’s a dirty gun, not lubricated enough, or maybe it’s my tendency to not let the slide fly back. If this is a dry gun or something strange is going on with the slide, do you think the gun could fire the first shot out of chamber? Or could one of the subsequent Cham wrings during firing not fully seat and that cause a partial slide engagement and the gun would fire out of chamber.

        I’m going to have ti videotape this and show this to my gun shop gurus and see what FN would have to say about this.

        G in michigan

        • g in Michigan

          Subsequent chambering was what I typed sorry about the typos above.

    • Matt

      This is only the second KB! posted I’ve seen in the last 3-4 yrs on FSN forum. The Third was a primer blowout it appeared, but it looked like it just damaged the plastic slide. Again from reloads..

      The original gentlmen’s was covered, and FN showed it was caused by a DC round, not OOB..

  • Orochimaru

    No disrespect intended, but why do you blame handloads for this?

    If I understand the sequence of events properly, the kaboom happened on the last round in an entire magazine of *factory* ammo. Only his first magazine was handloads — the last two were factory.

    I don’t understand why you’re blaming a handload –unless you don’t believe the original sequence of events.

    Apart from that — I agree with the cautions you have put forth on loading for this caliber. What you wrote is actually good advice for *every* caliber.

    • Could it be plausibly argued that overpowered handloads weakened the gun to the point where it finally failed, and it was only a coincidence that the round that finally put it over the edge was a factory load? Or is that just not the way the metallurgy works?

      • Orochimaru

        Joshua — that is certainly possible.

        I think, however, if the gun fired out-of-battery as the Original Poster indicates, it really wouldn’t matter if it did it with a handload or a factory load. Nothing good can come of it regardless of the ammo.

      • Absolutely. Any time a gun fires out of battery, bad shit is going to happen. I’m not qualified to make this judgement, but maybe somebody could examine the places where the gun failed to make a firmer conclusion.

    • My reason is anecdotal evidence. It seems that whenever there is a kaboom handloads were used.

      This could be because handloaders do a lot more shooting


      Because poorly made handloads cause problems

      • Aurelien

        I’ve shot 5,7mm ammo in both a P90 and a Five-seven. And i have to agree with Steve. The factory ammo is very, very hot. And it has to, because it’s a small case punching a lot of power.
        Handloading it, you would have to be really, really careful.

        Plus, the Five seveN is a really tough handgun. The one i shot was an old police model from the late 90s, with quite a lot of rounds gone through it. And no problems whatsoever.
        So to break one you would have to do something wrong.

        Still sorry for the shooter.

      • W

        Steve, I definitely agree!

        I’m not saying handloaders are stupid, im saying that I personally never liked the idea of doing it myself. Of all the KB’s i have heard of, the term “reload” was mentioned multiple times; there is a good reason why people assume handloads when a KB is posted (though one shouldnt immediately draw to wrong conclusions or make assumptions). With a bottle necked cartridge producing that much PSI in a handgun (a polymer one albiet), I would strongly recommend sticking to factory ammo. FNH, like other companies that give the same instructions, are not trying to be jamholes; they are trying to minimize injury.

    • ThomasD

      A round that fires out of battery is, by definition, not full seated in the chamber. This also makes it highly unlikely that the projectile is concentrically pointed into the throat of the barrel.

      When a round fires out of battery the case wall typically expands to the point of destruction – meaning the resulting pressure vessel is larger, and pressure gets released sooner than intended. The net result is the pressure peak is lower, and appears quicker, so less total energy is produced by the system, and most of what is produced gets expended out the cartridge walls, not down the barrel.

      The combined effect of all of this makes it highly unlikely that a round fired out of battery will result in the projectile leaving the barrel at the muzzle.

      The photos would indicate the projectile fully cleared the barrel. For this reason I doubt the events occurred as described.

    • Erwos

      Which is more likely: factory ammo exploded, or he accidentally put in a double-loaded handload in his magazine otherwise full of factory loads? Or that he was just shooting handloads and didn’t realize it? Remember, we already know he was shooting handloads. It’s not a huge leap to get one of them into his magazine.

      And, further: this guy is going to want to blame factory ammo anyways, because otherwise the only guy liable for this is him. He has a very powerful incentive for wanting to blame FN, to the extent that it might be playing with his memory.

      Of course, it could be that he’s right… but the statistics are not with him on this story. Best of luck in his surgery!

      • Duray

        I’m pretty sure a “double-loaded” 5.7 case would spill loose powder all over your bench. I doubt there’s a lot of extra room in that tiny case.

  • Massoud

    I hate to see this happen. Could you please follow up with how FN addresses this issue? I’ve been shopping these for some time and now I’m very unlikely to purchase one. I do own a FNP45 Tactical, which so far has been flawless….and by flawless I mean it’s worked perfectly and hasn’t blown apart in my hand.

    I hope you heal fast and complete and get back to the range soon.

  • xX v0oDo0 Xx

    As Orochimaru pointed out, the thread from the author says that factory ammunition were used in this instance. The V-Max FNH 5.7x28mm ammunition is made using a Hornady 40gr bullet, and is loaded in the United States by Fiocchi (it even says so on the bottom of the box). I own a Five-seveN pistol and have not ventured into using hand-loads, or remanufactured ammunition. The cost of ammo is high, but relative even if you consider reloads.

    I also wanted to point out that the factory magazines are 20rds. The thread says the shooter was using two 20rd magazines, and one 30rd magazine. Unfortunately for him, the use of an aftermarket magazine may have contributed to the failure of the firearm (last round failure on the 30rd magazine). Let this teach us that even a well-knowlged shooter can have mechanical failure. To eliminate risk, use factory accessories whenever possible.

    • Matt

      The OP claims the 30rd magazine was loaded with SS197SR, but on one site or another he admits it had been loaded for 2 months. How certain is he, that those were not his reloads, as he wont’ release data on what he was doing for reloads. He could have bene using 40gr vmax bullets. I see no reason to blame the magazine. If it caused a jam, it would not have fired the round.

  • Henry

    I tink that tis round was reloaded wrong , because some similar hapened in my Thompson Carbine semiautomatic cal 45 ACP reloaded ammo with 250 grains RNFP ,te round kabbon in the chamber because is not plased in the chamber if not only at 1/2 case broken the block…

  • hojo

    I agree with Orochimaru. I’m as eager to blame hot loads as anyone because I love FN, but “hot loads” or not, if the primer is struck without the case in the chamber, bad things will happen. If it were a hot load, I would expect to see damage to the chamber.

    • Nadnerbus

      True enough. I have no personal experience with kabooms, but it does seem that every time one comes up on the Internet, hand loads are involved somewhere in the process, which always makes me think of those as the most likely culprit. But if the weapon fires basically a rifle cartridge in a pistol action, I can see how an unsupported round could lead to bad things no matter its origin.

  • Bob Z Moose

    I never understood the “void warranty if reloaded” thing. Seems like lawyer bs to me. If a gun can’t handle reloads (I’m not talking over pressured proof loads), then the gun isn’t as safe as it should be. The gun needs to be able to take some decent abuse when it comes to ammunition. If it’s weakened so badly after a mag of handloads that it can’t stand up to factory ammo (which is usually pretty tame), then I have to wonder about the quality of design, engineering, manufacture, ect. I don’t think other bottlenecked rounds (357 Sig, for example) have had major problems like this.

    The 5.7 ammo is outrageously priced anyways. How do they expect someone to get decent range time with factory ammo without a 2nd mortage?

    Just my opinion, but I never like the 5.7 to begin with. Miniature rifle round in a handgun? Could see a ton of problems.

    For the guy that had this happen to him: God bless and I hope you make a speedy recovery. It’s not fun being sidelined from the range for any reason, much less something like this. 🙁

    • Aurelien

      The Five-seveN was a military/LE only gun for quite a few years. It was designed to run around precise parameters on armor-piercing SS190 ammo.

      It stands to reason that FN wanted to be protected against any liability, and handloading is a liability (you can control what loads the professionals run, not what the public will run if left to their own devices).
      Thats just one step up from the ‘read the damn manual first’ tags.

    • Nater

      It’s mostly because the manufacturer has no control over the reloading process. It’s very easy to screw it up, especially in high pressure cartridges. Bullet seating depth is critical.

      If you were a builder of rocket engines, would you warranty one that was running home brew rocket fuel? I sure as hell wouldn’t.

    • W

      “The gun needs to be able to take some decent abuse when it comes to ammunition. If it’s weakened so badly after a mag of handloads that it can’t stand up to factory ammo (which is usually pretty tame), then I have to wonder about the quality of design, engineering, manufacture, ect.”

      The handgun is engineered to take a certain powder load in a cartridge. Once you exceed that, then you are surpassing the parameters of the design. You are acting unfair and unreasonable to the weapon design.

      “I don’t think other bottlenecked rounds (357 Sig, for example) have had major problems like this.”

      There have been kabooms in every handgun type and caliber. I have rarely heard of a five seven even kabooming. Its interesting that i have never seen a kaboom with factory ammunition bought from the store and shot on the range in a reasonable amount of time.

      The 5.7 ammo is outrageously priced anyways. How do they expect someone to get decent range time with factory ammo without a 2nd mortage?

      Just my opinion, but I never like the 5.7 to begin with. Miniature rifle round in a handgun? Could see a ton of problems.

      For the guy that had this happen to him: God bless and I hope you make a speedy recovery. It’s not fun being sidelined from the range for any reason, much less something like this.

      • W

        I accidentally added unneeded quotes. To finish my last statement, if you cannot afford to shoot it, then don’t buy it. A very old and wise man said that to me once.

  • Brice

    Notice that the barrel does not appear to be damaged. The chamber is intact. I’d blame a hand-load if the chamber or barrel had been damaged. The 5.7 round is a very high pressure (50k PSI) round, without the chamber to support the brass, you’re going to blow stuff up. $2000 dollar pistol, gone. $12,000 to $15,000 dollars in medical bills. Who knows how long for physical therapy. That’s a bad deal all around. I hope I never see a gun do this in person, the one I saw with a .308 round in a .300 mag chamber was bad enough.

    • Chucky

      An incident similar to this happened some 3-4 years ago but was found to be caused by bad handloads. The thing with the 5.7 pistol is that it does not have barrel lockup. On a gun that does, say a Glock or 1911, an overpressure handload will bust the barrel as the gasses have nowhere else to go. On a 5.7, all that excess gas comes out the back and into the shooters hand.

      • ThomasD


        The pistol did not fire out of battery. A too hot round fired in battery, the slide moved rearward while significant pressure was still present, the rear portion of the case left the chamber, the excess pressure then blew out this unsupported area of the case.

        I think it highly unlikely that a round which fired out of battery would be so properly fire formed into the chamber, or that there would be enough contained energy to clear the projectile from the barrel.

  • Ted

    Please tell me that that is not the man’s blood on the barrel there…

    I don’t know enough about how the Five-Seven is designed to say, but I feel like, if the weapon firing out of battery was the cause of the explosion, then it might be a problem with the magazine, not the handloaded rounds. If I had to guess, I would say it was the follower, grabbing something on the slide’s return that sapped it of its forward momentum, and preventing the cartridge from sealing.

    Or it could just have been a glitched factory round. I’ve seen those before, rare though they are.

  • roger

    I would never hand load this cartridge, too high pressure.

    I will pass on the 5-7, I have wanted one for some time, but will go with my gut and get a metal gun.

    Sorry about your hand, I hope you make a full and speedy recovery without too much discomfort.

    • Komrad

      The Five-seveN pistol has a metal slide with a polymer overmold. Also, steel guns are no less susceptible to ka-booms than polymer guns and they are not significantly safer than polymer if a ka-boom occurs.

      Instead of making a generalized assumption on one anecdote, you should look at data for ka-boom rates if you are really worried. Even then, ka-booms are exceedingly rare without loading mistakes of some kind (be it at a factory on your press).

      • Jeff

        But as you can see the slide, though bent is still intact, the polymer overmold frame not so much. As an engineer, I’d say this is precisely what a steel or even aluminum frame would deal with better. I’m not blaming the polymer, just saying each has it advantages… Even still a metal frame wouldn’t necessarily have made a difference, merely delaying the day an overpressured round did the same. With sufficient enough overpressure even a metal frame can blow and would be that much more catastrophic due to heavy shrapnel.

        Moral of the story is handloading is “at your own risk” and overpressured loads will weaken and damage polymer frames more quickly than traditional metal ones.

  • PCP

    Delayed blowback system are notorious to be hard on brass and to be extremely pick with pressure, bullet weight and burn speed. The whole system is finely tuned to work within a narrow margin of variables in terms of ammunition, so it’s no surprise handloading and hotloading would be ill advised. Specially in a handgun since the thing wont be as sturdy and tolerant and probably as a rifle.

    I also hope that nobody starts to call the Five-seveN a hand grenade like the Glocks were. I don’t think that has ever being in all the history of firearms a weapon model that have not suffered at least one kaboom.

    Also can anyone confirm if the Five-seveN barrel is fixed like in most DB systems or if the barrel recoild like some claim. I’ve saw some FN pattents for a hybrid system (that probably works on the basis of Belgian Elven Magic like the F2000 ejecting system) for a handgun but I’m not sure if it’s the same.

  • ruben

    Leave reloading to the experts.

    • Properly done, reloading is quite safe and the advice to “leave it to the experts” is simply not valid – if you mean that “experts” exclude knowledgeable home reloaders.

      However, there are some cartridges that simply require more care and more understanding of the issues than others in reloading. Frankly, the 5.7 has a lot of these issues given the narrow operating range of the guns chambered in them, the smaller case capacity and other tolerances together with the operating pressures. I reload a lot of calibers but would not reload 5.7mm.

  • Draxanoth

    Aren’t most modern handguns designed to prevent OOB strikes? I don’t think mine even allows the trigger to reset if it doesn’t feed correctly.

  • Nater

    I’m blaming the hand loads and for good reason. Seating the bullet too deeply will cause an increase in pressure in any cartrdige. This isn’t a huge issue on something like 9x19mm or .45 ACP because the pressures are low to start with. However, the 5.7x28mm FN is a very high pressure cartridge (as are .40 S&W, .357 SIG, 10mm Auto, ect). To top it off, it’s bottlnecked making reloading even more difficult.

    It might not have been a handload that caused the actual KB, but I’d bet on a bad handload or a succession of them weakening the pistol to the point where failure became inevitable no matter the cartridge.

  • strongarm

    Hammer firing pistols are cocked during the backward travel of slide
    whereas current striker firing pistols with exception of Russian GSh 18
    cocked during forward travel of breechbolt. Therefore, out of battery
    firing possibility of a Glock type autoloader is less than any kind of a
    hammer pistol like FN Five-Seven.

    Positive disconnectors prevent out of battery strikes some 3 milimeters
    to the barrel and in most cases this is absolutely safe. FN Five-Seven
    has also had a positive kind disconnector and battery off firing is nearly
    impossible for such a gun.

    FN Five-Seven works in rather different delayed blowback system very
    similar to old Italian Glisenti pistol in which a pivotaly mounted lever in
    receiver propped over both slide and rearward movable barrel with at
    different heights that transmitting the speed of recoil on different stages
    as providing a suitable separation of barrel and slide for positive extraction.

    On delayed blowback firearms, breechblock begin to open while the gas
    pressure is on high levels and most of them contain chamber grooves for
    empty cases not to stick into chamber inside walls, Five-Seven has not
    had such a facility and instead, the cartridge cases are covered with a
    slippery clear plastics somewhat oiling chamber’s inside for only one shot.
    This is the main reason for manufacturer’s taking these guns out of
    warranty in using reloaded ammunation which not carrying slippery plastic

    In firing of an original Five-Seven cartrigde, the slide is pushed rearward
    by fired case and the delay lever propped over the slide slows down the
    rearward travel of barrel as providing a secure seperation of members with
    safe extraction of fired case. Both slide and barrel recoils in different
    speeds in this case, but, if a handload is used, the case sticks within the
    chamber as resulting the slide being pushed backward by mass of barrel
    as same speed with it and bigger motional energy than normal firing and
    this may give the slide more velocity as causing case separation.

    Reloaded ammunation may not stick in the chamber but leave some metal
    particles swaged therein and in turn, these residues may cause a factory
    load to stick in chamber as resulting case separation a well.

    This event may be such an origin.

  • G

    “Shooting Times once published an article about reloading the FN 5.7×28mm (since taken down, maybe for liability reasons).”

    The website of Shooting Times had a complete overhaul some time ago and most, if not all, old articles were taken off-line at that time. The old articles have slowly been reappearing online since then. I assume that the 5.7×28 article will appear online again some time in the future.

    “Using reloaded ammunition in PS90 and Five-seveN firearms voids any warranty and any liability of FNH USA.”

    You can find this warning of Sako’s website:


    As use of proper reloading procedures are beyond our control, we assume no liability or give any warranty against damages or injuries caused by use of reloads. Improper and poorly made reloads can ruin your rifle. They can also be dangerous to the shooter and standers by and may cause serious injuries or death. No rifle manufacturer including ourselves gives any warranty on rifles when reloads are used.”

  • I read the fellows post over at the FN forum. i agree with your conclusion that a handload caused this damage. On the thread, he maintained that it was an FN factory load that caused the kaboom, after shooting some handloads. Color me skeptical, as I think it was a handload loaded too hot.

    The FN 5.7 is a fine pistol, but I prefer to shoot the FN factory ammo in it. As always, it’s a good idea to wear shooting gloves in addition to eye and ear protection with any gun.

    • Matthew S

      Handloads??? What is with these guys using handloads for everything. Im sure there is something in the manual about not using handloads.

    • W

      I think with a cartridge as powerful as the 5.7×28, I would remain dubious about the benefits of reloading.

      And yes, it does say in the manual to not use reloads, specifically because it will void the warranty. To some people, it is worth the few extra dollars to significantly raise the risk of exploding their weapon at the risk of expensive personal injury. To me, that is disingenuous; I have never been a fan of reloading anything.

      • Phill

        The advantage to reloading isn’t JUST performance. The advantages are also economical.

  • PCP

    Any idea if the Five-seven chew brass like the G3 and other delayed blowbacks? Information on the mechanical parts of this handgun are quite scarce.

    • Matt

      You’ll have occassional dinged mouthes, but brass is usually always in good shape.

  • JesseL

    Funny how people keep mentioning high pressure and a bottlenecked case as reasons not to reload for 5.7×28, but I’ll bet they wouldn’t have such compunctions about reloading for, say, .223 – bottlenecked and lots more pressure.

    Not saying there aren’t any good reason to avoid reloading for that particular round and pistol, but the pressure and bottleneck aren’t among them.

    • Chucky

      Google “AR-15 kaboom”. You could be reloading for decades and be really good at it, but all it takes is that one round where you made a mistake.

      • JesseL

        Sure, things can go wrong reloading for any round or firearm if you’re not careful. Are you suggesting that nobody should ever reload?

      • Chucky

        I’m suggesting that handloading can be too dangerous to do with certain ammunition where human error is greatly magnified especially when the firearm manufacturer themselves have spent a lot of time and money to determine just how small the margin of error can be.

      • JesseL

        I suggest you reread my original comment then. That thin margin for error may be a good reason not to reload for 5.7, but that’s a very *different* reason from just the high pressure and bottleneck.

      • W

        “Funny how people keep mentioning high pressure and a bottlenecked case as reasons not to reload for 5.7×28, but I’ll bet they wouldn’t have such compunctions about reloading for, say, .223 – bottlenecked and lots more pressure.”

        They don’t because it is a classical case of pistol versus rifle. I would rather have a kaboom with a AR15 than a polymer pistol that fires high pressure bottle necked ammunition (i.e. Five seveN). This guy guy was seriously injured by this kaboom; Im sure it is possible, but i have never heard of similar injuries by a AR15 kaboom.

        I have never known anybody personally that has had a kaboom, though it seems to me even the most experienced and seasoned reloaders make mistakes and blow up guns. I remember reading on this blog about a AR15 kaboom that was caused by switching rifle power to pistol powder while reloading. A very human mistake. I personally have a budget for factory ammo; its more conducive for my time to use factory ammunition.

  • Vaarok

    Would the increased, though admittedly tiny mass of the sight possibly have influenced the slide lockup and recoil characteristics?

  • Zermoid

    The only KABOOM I’ve personally experienced was an out of battery firing of a Universal M1 Carbine, a friend was shooting it slow fire at a target and I was standing right next to him, I had just looked over at him after his last shot and noticed the bolt was at an angle instead of laying flat, I yelled for him to “Don’t Shoot!” but it wasn’t in time, he squeezed it off in the middle of the word shoot. The bullet DID exit the barrel, but the bolt lugs broke off, not sure if upon firing or being slammed into the back of the receiver, we never found the extractor, and had to knock the front half of the brass out of chamber with a cleaning rod. Other than the bolt the gun survived unharmed, I replaced the Universal bolt with a properly headspaced GI bolt and the gun worked flawlessly for many years after. Did have to alter the “tang” on the GI firing pin, otherwise drop in fit.

    My opinion on that particular gun disaster above is that he would have only had a stinging hand and possible temporary numbness if the pistol had a steel frame instead of plastic. Sure the frame would probably be bulged and still ruined, but the collateral damage to himself would be much less. Steel tends to bend where plastic shatters, which is why I will probably never own a plastic framed handgun. Just don’t trust it to stand up to the stresses of a handgun long term.

    • mosinman

      to be fair, plastic framed guns have come a long ways. and any firearm can shatter into peices. but i agree with you , i prefer steel. im willing to sacrifce lighter wieght for a more wear resistant matieral

  • Alan

    Q: Does FN consider Elite Ammunition to be handloads? If so, does Elite Ammunition come with any kind of warranty?

    • jack

      FN does not consider it factory ammo. It will not be warrantied by FN should your firearm malfunction while using it. I do not know if Elite has insurance for something like this or not. I sure hope they do though.

  • Lance


  • Davey

    Better late than never:

    Note (IMPORTANT) that the barrel and chamber are intact. Also note that there’s a substantial amount of brass extending out past the chamber. If the cartridge had chambered properly, all you’d see is a missing case head – assuming that you could find the parts because the chamber would have burst.

    The amount of brass that is hanging out is pretty much proof that the cartridge fired before the cartridge was fully chambered. I can’t think of a way that the cartridge could have been in the extraction cycle and fired.

    • Matt

      Impossible to fire OOB. Super Unscientific tests shows while the hammer will drop at say .160″ rearward movement, firing pin block is active..

      .034″ rearward is as far back as the slide will fire a round, and the barrel movement at that measurement is neligible. This is definately not an OOB. Look at the first KB! of the FSN. His barrel was intact too, when infact he Double Charged his rounds.

      • Sigivald

        Impossible to fire OOB. Super Unscientific tests shows while the hammer will drop at say .160″ rearward movement, firing pin block is active..

        Doesn’t that mean that “impossible to fire OOB” really means “impossible … unless the firing pin block has failed”?

      • hojo

        Out-of-battery can (and does) still occur if the firing pin sticks “out” on a dirty gun.

      • Tinkerer

        The operative word being “dirty gun”. It would take an awful lot of grime to stick the pin block on the open position, and a responsible firearm user should make sure his firearm is in correct operation order -that includes cleaning the weapon once in a while.

      • hojo

        If the firing pin sticks forward, the pin block cannot reset, and becomes irrelevant.

  • Mike Knox

    That is the most severe Catastrophic Failure I have ever seen, so far. I’m wishing ‘fairchase’ a proper, speedy recovery.

    Stuff blowing up in your hand is quite a horrible thing, especially when unexpected. The closest I can relate to this is a .40 S&W round blow-out on a hot day a few years ago. The round was badly corroded after stored in open sea air. I made a mistake fondling it with my sweaty fingers thinking it’s a harmless dud. I was wrong.

    I’m sure it won’t compare to ‘fairchase’s’ CF, he has nerve damage. Wishing you the best..

    • Mike, did the round explode in your hand?!?!?

      • Mike Knox

        A slow burn then the primer blew off. The propellant was caked with some salty residue. I felt it getting hot so I yelled “hot round” then ‘BAMPF’! I got a burn on my figners. It was like a firecracker on the dinner table.

        It was quite embarrasing, I was there to teach my girlfirend how to use her Beretta 96..

    • hojo

      THAT is spooky. I had no idea such a thing could happen. Glad it heated up first or presumably it could have been a lot worse. Anyone know the mechanism behind something like this?

      • Mike Knox

        All I know was that the rounds were stored in it’s cardboard box on a shelf with garage and gardening stuff. The room was open air facing the sea..

  • John Doe

    I really wish Glock made a 5.7mm pistol. Not a fanboy (okay, a little bit), but Glock polymer is pretty damn durable and I trust my hands with it.

    Also, aren’t you supposed to use factory ammo with 5.7, since handloads are tricky?

    • jdun1911

      What’s tricky about reloading 5.7 ammo?

      Weight the powder. Put the powder in the case. Put the bullet in the case.

      I have seen the reloading data sheet and pressure of the 5.7 but that’s a long time ago. With that said I never reloaded 5.7 ammo before.

      • John Doe

        “With that said I never reloaded 5.7 ammo before.”


      • jdun1911

        I have over 20 years of reloading. Tell me what so complicated about reloading 5.7?

        Don’t be stupid. Reloading is the same process for every calibers. There nothing magical about it.

      • Tinkerer

        I believe it has more to do with the type of action used in the P90 and the Five-seveN than with the specific caliber. In a locked action, an overpressured handload wouldn’t do what it did here.

      • jdun1911

        It doesn’t matter what action it used. The reloading process is the same for every handgun/rifle cartridge.

        Pop the used primer out.
        Trim the case.
        Resize the case.
        Put a new primer in the case.
        Weight the powder.
        Put the powder in the case.
        Put the bullet in the case.
        Crimp the case.

        People should not post what they don’t understand. Morons leading morons is bad. There nothing magical about reloading 5.7.

        Reloading is a skill that every person that is into firearms should acquire. Those that actually do reloading knows that I’m right.

      • W

        there are shooters, including myself, that deliberately choose not to reload because of the risk of catastrophic damage done to the weapon or myself. Ill go so far as saying there are reloaders out there that can handload cartridges better than the factory, though that is a risk i am personally unwilling to take.

      • Mu

        5.7 cases are coated to allow proper function of the gun. Reloading the case, especially after extensive cleaning (and as a blowback action there’s usually a bit of gas leaking around the case, they are typically very black, at least in my P90), will damage or remove the coating and is known to lead to function problems. At $.40, it’s a rather expensive round, but it’s the only caliber I don’t touch for reloading.

  • Duray

    Gotta love all the sage advice telling us not to handload. Handloading is no different from owning a gun; if you’re a responsible person who can follow instructions and common sense rules, you’ll be fine. If you’re an irresponsible clown, you’ll get someone hurt. People seem to assume that reloading is some sort of uncharted voodoo that only results in unpredictable super-pressure ammo. There’s no reason handloaded ammunition can’t be perfectly safe if you follow your recipe and check your work as you go, just like there’s nothing dangerous about shooting a gun if you keep your finger off the trigger and watch your muzzle. Incidentally, I’ve seen a nice Sig/Hammerli Trailside pistol rupture a barrel from a factory Federal .22 squib. Are rimfires just too risky? Should we all stay away?

    • Chucky

      “if you’re a responsible person who can follow instructions”

      Using reloaded ammunition is at the top of their do-not-do list in the instruction manual.

      • DDD

        Every firearm’s manual has some type of “do not use reloads” warning.

      • jdun1911

        EVERYBODY that is into firearms should learn how to reload. It is a rite of passage.

    • I do a lot of reloading. However, the 5.7mm is a pretty spooky round to reload for, especially with the behavior of the guns chambered in it.

      • jdun1911

        What is so spooky about reloading 5.7? Do you need voodoo magic rituals to reload 5.7?

        You reload 5.7 the same way as any handgun cartridges. Look at the reloading data and make sure the powder weight does not exceed it.

      • jdun1911

        I’m at work so I don’t have my reloading data books/sheets with me.

        Gun and Ammo reloading data range on 5.7 is standard. The margin of errors is standard.


  • Mike Knox

    Seriously? a lot of guys are more concerned about reloaded ammo than Fairchase’s injury?

    • fw226

      Well, I can’t do anything about his injury. But if I was thinking about getting into handloading, I might want to know more about it. So, sortof.
      I sure hope he sees improvement, but I imagine it’s going to be a long road. Good luck dude.

    • hojo

      I think the concern is how to prevent this in the future. The injury is unfortunate, but there’s little we can do about it now. We CAN try and find ways of preventing similar injuries in the future.

  • drewogatory

    Could have been setback just as easily as overcharging a reload. With the tiny case volume it wouldn’t take much and most folks don’t check OAL on factory ammo, I know I usually don’t. Looking at the loading data there appears to be a decent margin between safe and max loadings, well within the margin of error of even cheap scales (assuming he wasn’t throwing his charges, which would be unwise to say the least).

  • Jay Dee

    Reloading related failures are generally categorized as either an unintended overcharge or a hot load switched between guns. The 9mm is especially susceptible to the latter. The former is best prevented by using a highliter in your reloading manual and choosing a powder that mostly fills the case.

  • Martin (M)

    First, I hope the shooter recovers.

    This is textbook OOB. Despite so many people quickly jumping on the handload failure bandwagon, you cannot deny the photographic evidence. An overloaded cartridge will not push the case out of the chamber and mushroom it around the assembly. It will split the barrel, it will blow the rear off the case, but it will not push the brass out of the chamber and rupture it. Take a second look. That round detonated without being fully in battery.

    • Tinkerer

      Remember: it’s a delayed blowback action, not a locked action. An overpressured round will push the slide back faster than it is designed to do with adequate ammo, before the pressure drops to safe levels.

      This is the chain of events:

      -overpressured round is fed.

      -slide closes in-battery

      -hammer strikes

      -overpressured round is detonated, pushes the slide back too fast, leaves the back of the case unsupported while the pressure is still too high

      -catastrophic failure.

      • Martin (M)

        That all sounds very reasonable, but the speed of the explosion (especially in a handgun) would cause a failure long before the action begins to move. The time it would take for the delay in your scenario would allow for the round to exit the barrel, relieving the pressure. This firearm appears to have been blown apart because the round detonated out of battery.

        We’re not talking about the rear of the case being popped off, a bulge, or an extraction failure. That handgun is destroyed, and the operator sustained concerning injuries.

  • bill

    That does it…I was considering a FiveSeven but after seeing this, no way. I’ll stick with my 1911s…they lock-up!

    • Chucky

      Better not look at 1911 kaboom pics then, or of any firearm for that matter.

    • W

      since the five seven is kabooming left and right…LMAO!

    • Ajay

      I just kaboomed my pants!?!? Sorry, I just felt like saying kaboom.

  • Mike Knox

    I always thought the FN FiveSeven had steel inserts in the frame like a SIG P250..

  • Brian

    From Ivan Chesnokov:




    • trollbuster

      This Ivan Chesnokov is the trolliest troll ever.

      I wish this were funny like some of his other stuff.

      Here’s a bunch of his “gold”.

      • trollbuster
      • roger warrington

        I was going to get one but I do not wish for it to blow up on me. so I stick with a 1911 45acp. . I have a browning 380 from the eary 50s and a cz 32. nazi auto all is like mint. so now I stick with American or I will look to see what is good at the time. the gun is only as good as the person that is pulling the triger. A black powder 6 gun is just as good , it is the shooter not the gun… they make potato guns, I think for use over there.

    • Mike Knox

      I hope this guy gets bit by cancer and drowns in his own toilet..

    • Currahee101st

      AKA Ivana Blojobski. I have a FN 5.7 and I do like Armani suits,your point is?

    • Sgt. FiveseveN

      Same wound? The 9mm over penatrates. An accurate shooter returning fire in a crowded area risks more civilian casualties with a 9mm versus a 5.7, the body is mostly water and the light round can easily pass through doors and thick clothing yet slows down greatly when it hits the body and greatly reduces the lethality of the round after it passes through the body. Your comment sounds like a hurt ego. That’s very American of ya yet you don’t sound like your from the US.

  • lauren ross

    The owners manual states the ss195 27 grain round is to be used in the 5.7×28 pistol, as I recall it is on page 25 of the owners manual. I had discussed that with the Factory rep in my area since I use a lot of ammunition for my 5.7×28 pistol and for my PS90. He told me the PS 90 can shoot the SS197 40 grain or the SS195 27 grain, but the pistol should only shoot the SS195 27 grain, if you have some of the pre-ban SS192 27grain can be shot in the pistol also. Not all gun stores carry the SS195 27 grain, I get mine from the FN rep once a year, I have shot thousands of rounds, and have the FN rep inspect my guns every year, and never a problem yet. The 40 grain may of made too much pressure and caused the Kaboom. I pray that he has a speedy and full recovery.

  • Anon

    I like how everyone jumps to conclusions and basically calls the poor guy who almost got his hand blown off a liar when he specifically said that he was using factory ammunition.

    The truth of the matter will come to light soon enough, after he tries to get FN to pay for his hospital damages/replace his gun, so what’s the point in speculating like a bunch of bored housewives? Why the eagerness to make baseless assumptions when you don’t even have the full details of what happened?

    That and the amount of “sage advice” and mother hennery in this thread is just staggering, comes with the culture, I guess.

    • Seamus


  • Being a former (retired) Army ground pounder, I’ve been using (and I mean using!) FN weapons for many years, albeit mostly machine guns. Ultimately the high, high quality of their guns that I’ve jumped out of planes with, dragged through red clay -and then fired hundreds of rounds through- was one of the deciding factors for me, when laying out the money for the purchase of the 5.7mm. I am not an expert reloader although I’ve done it. I am an expert hand gunner but don’t know everything. My opinion is that based on the extremely rugged nature and superior design of all/any FN systems I’ve ever used, I highly doubt that this pistol blew up because it is a polymer-based design. I also doubt it fired out of battery. I am not bad-mouthing the original author but have serious doubts as to the accuracy of his comments. Two plus two is almost always four; for that reason I respectfully submit this incident was the result of firing improperly reloaded ammunition and in this case, inadvertently mixing it in with standard factory ammo. One thing no one else has mentioned is the appearance of the exterior surface of the upper slide assembly. It appears to be generally dirty which is somewhat understandable but only somewhat. But it also bears the distinct appearance of gun metal that has been heated to nearly -or surpassing- failure. I have only ever seen a barrel look like that after a weapon has been fired at or beyond it’s cyclic rate of fire, which brings to mind the question: what is the cyclic rate of fire for an FN 5.7mm pistol? Is it possible to surpass that rate, especially using reloaded ammo? And if I’m correct, then the cause of this failure was still operator-induced. Either way, we all make mistakes so let’s try and take at least one positive thing away from his mistake. Know your weapon and it’s limitations, it’s just a machine.

    • Dr_Jean_Claud

      You appear to be right on the money, in that:
      1. The photo doesn’t match the story of how the round/pistol exploded.
      2. The story is way to close to what you would hear from a typical “victim” trying to get money out of a manufacture–the giveaway is in the wording of his “wounds,” i.e., not typical of an actual “accident” victim.
      3. To support this is the overly detailed description of what medical procedures will be needed, vs. a normal victim who doesn’t know in advanced as to WHY the “accident” happened, whose details were omitted (for whatever reason).

    • Josh

      Ahem. I know this is a two year old comment, but I can explain that dirtiness. Having done a small amount of work with low explosives and such, the technical term for it is “Dross”. It’s basically similar to the carbon fouling you might see when cleaning a gun, but it starts off almost like a gas and ends up as a residue on a surface that was near the explosion when it occurred. It has a very distinctive grey-ash look, similair to dirt, but much stickier and very caked onto the surface. As for the barrel…… That looks like blood to me.

  • steveb.

    Is the 5.7 still being manufactured?

  • Scott

    Using a reload voids any liability ? That’s a ridiculous statement, regardless of how many times the manufactor says so. As a matter of law there is no such thing as voiding liability. In fact when a company makes such claims it just gives me something else to present to the jury, “they knew there was a problem and continued to sell it , exposing my client to sever risk”. Stick to evaluating guns, your understanding of real world litigation is rather poor. You obviously aren’t anl attorney.

    Real world: gun makers settle quickly and quietly because they know the typical jury is not sympathetic to the industry.

  • robbie


  • gandog56

    I don’t know, he was pretty explicit that it was factory ammo. Where would a reloaded round come from if he doesn’t even reload? Hope whatever they are doing to fix his hand works. Good luck on that, dude!

  • tim

    Dude get a lawyer. Period. Don’t think that FN doesn’t have lawyers on this already, waiting and hoping you blow the statute of limitations.

  • james

    James/NC –
    “The explosion” occurred on the last round of a 30 round mag loaded with the factory 40gr v-max stuff.” _ 40 gran?!!! – hope I’m wrong on this but, is not the FNH 5.7mm pistol engineered for only the 27 gran rounds and not the 40 gran rifle rounds! – over pressure YES and Operator error.- like cambering a 300 blackout in a 5.56.

    • Bob Cobb

      The explosion happened with homemade reloaded 5.7 ammo, the original claim by the shooter was a lie in order to avoid being voided. He may have been shooting vmax 40 grain but it wasn’t shelf ammo, it was reloaded. I’ve shot tons of 40 vmax in both of mine and no issues. Thankfully for him he wasn’t killed and FN was too kind and replaced the gun he destroyed.

    • Jesus H. Goldberg

      I wasn’t aware of the fact it was engineered for “grans” at all.

  • Bob Cobb

    This specific case has already been resolved. FN did testing and found the 5.7 IOM, USG and MKII which are all the same gun internally, did not fire out of battery but the shooter reloaded improperly and it was his own fault. Not only did FN prove their firearm design is superior and did not malfunction, but they tested and destroyed a few of their guns in the process, and they even sent this goof a new FN even though it states in their literature that reloads VOID warranty and liability.
    Most who reload 5.7, which is about 1% of the reloading population or less, do not exceed the posted working loads, the few which includes this guy, experiment and tempt fate by going over the recommended load specifications to get another 200-300 fps. While the internet rumor mill will say there are other catastrophic failure cases with the FN 5.7 handgun there are no others on record. This goof knowingly loaded hot loads trying to get more velocity in a caliber and gun already at the max and he paid a small price, he could of easily killed himself all in the name of having a personal load he could claim is the hottest. I’ve fired my IOM and USG over 2,000 rounds each using various “shelf” ammo, never reloads, and not a single malfunction.
    This guy thought he was smarter than FN and their engineers, he wasn’t.