Electromagnetic Interference caused K-11 KABOOM

A Korean news website has revealed that in October last year a S&T Daewoo K11 exploded after one of its 20mm grenades was prematurely detonated. The soldier who was operating the gun suffered cuts on his hands and face. Ironically another problem with the gun, the poor lethality of the small 20mm grenades, saved the solider life.

The Korean Department of Defense attributes the problem to electromagnetic interference from the Fire Control System. Reading between the lines, it sounds like it may have been a software bug with the FCS.

I am troubled that it was even possible for the grenade to detonate. The grenade it supposed to be spin-armed, ensuring it has been fired a certain distance before detonating. Maybe a bug in the software (either on the grenade or on the FCS or both) allowed the grenade to be armed at a distance of zero, allowing it to be detonated in the barrel.

Kindly translated from Chosun.com by Uribury …

Electromagnetic wave interference caused K-11 rifle explosion

October 14th, 2011. A K-11 rifle exploded during field test.

Shooter, private second class Lee of ROKA 32nd div suffered some cuts and scrapes on his hands and face but not life threatening injures

This accident caused another delay of K-11 rifle production.

Early 2011 K-11′s poor quality control and lack of reliability caused production delay, after trouble shooting and more field test, it was said to begin production in november 2011.

And this accident messed all up.

Department of defense made a team to inspect this accident and recently announced electromagnetic wave interference between rifle FCS and 20mm ammo fuse caused the accident.

This is what happened. The transmitter which sends trigger signal to ammo fuse was not properly fixed because of design defect.

And the shooter squeezes trigger a little before fire, it interact with not properly positioned transmitter and send wrong signal to 20mm ammo fuse.

It caused 20mm round explosion in the barrel.

Fortunately K-11′s titanium barrel or 20mm ammo’s lack of lethality saved the soldier.

An official of DEPA(Defense Acquisition Program Administration) which under DOD said that all 246 already produced K-11 will be recalled and will change triggering system design, FCS program.

Plus, there will be improvement on short battery life in cold weather and laser range finding trouble on rainy day will be fixed on next version of the rifle.

Until June all the improvement will be examined through performance test and confirmation of technology study committee then will judge field the weapon or not.

[ Many thanks to uribury871 for emailing us the link and translation. ]

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.


  • Chris b

    In small words please explain to me why you would bother with electrical detonation on small arms? Was the term “Mil Spec” missed on the terms of construction? Tech for tech sake…….

    • Nadnerbus

      If I understand your question correctly, it’s because they are programmable rounds for distance so as to be used in a counter defilade situation. The distance to target is lased by a range finder, the computer instructs the round, and in the case of the American version of this weapon, the operator can add or subtract distance in increments of five or ten feet I think to fine tune it.

      So, not a proximity or contact fuse. But being able to arm before leaving the barrel seems like a huge safety problem.

  • Iv’e never fired any of these new whatever you call them weapon systems but being a fairly young guy and having been in the military I remember a statement from a drill Sargent. “An EMP device is one of the greatest non lethal weapons available” at least for the enemy look at all these American soldiers with there Aimpoints, EOTech, etc take that away and they can’t aim for shit. Sometimes making war easy is not the best Idea. That’s why I like shooting with iron sights not that I don’t like all the new tech but a M4 & M9 with iron sights = simplicity. To be fair I like shooting with a red dot sight but I do enjoy the challenge of making a shoot with iron sights. Not that I’m dissing technology I see the advantage of GPS/laser guided missiles vs launching and praying but… umm its hard to explain I hope you guys get the point I’m trying to make.

    Traction control is nice but sometime I like to do a burnout.

    • Mike Knox

      This isn’t about EMP but electromagnetism. the Latter is caused by electricity flowing through a conductor generating a magnetic field which can influence other electrical flows or upsetting charges. The CF reported in this article is an electrical fuse circuit interfered by such a field.

      It’s basically the same reason Cellphones are requested to be turned off in an airplane, phones kept a distance from a radio or solenoids from microchips.

    • Nater

      All of what Mike said, but to add to it.

      To generate any significant amount of EMP, that needed to cover more than a rather small point target, you need a lot of energy. By a lot of energy, I mean a nuclear weapon. In such a scenario, your EOTech 553 dying is probably not going to be of primary concern.

      As for the tired old “I only like iron sights” argument. Trying rapidly engaging targets at night with irons. It’s also incredibly difficult for a human being under the so-called body alarm response to resolve a front sight on a rifle. Red dot sights are simply an order of magnitude more effective for the aiming of small arms. It’s funny, because the soldiers that first started using modern red dot optics on their weapons were also the best guys we have (1st SFOD-D). Clearly not the type of guys that need a crutch to shoot a rifle well. OEGs go back to the Son Tay…because they wanted a much more effective way to engage targets and night.

      I don’t disagree that soldiers need to know how to use irons and use them well. Optics can and do break. When, and if, EMP weapons can be made effective without nuclear explosives then this might be a problem. As for now, it isn’t.

      • Andrew

        Nater – you need to look up what it takes to generate an EMP since it’s clear you don’t understand the mechanics – you have little to NOTHING to worry about from the rest of the thermal/radiation effects since an EMP strike is caused by detonation of a nuclear device in upper atmosphere

        Basically one device high enough above the US say 300 miles up would kill almost every piece of non-hardened equipment in the entire country – the range of the pulse is 1000’s of miles – yet the direct effects of the weapon would likely not kill anyone


      • Nater

        The point is nuclear weapons are being tossed around. I didn’t say anything about heat/blast from the weapon that triggered the EMP. However, the main use for high altitude EMP is to disable defensive systems covering an area to be attacked with ground bursting nuclear weapons.

    • Justin

      Valid point. However, I think most weapons that have red dot, acog, etc equipped in the military have some sort of BUIS (Back up iron sights).

  • Witt Sullivan

    They had premature detonations with the grenade launcher in the OICW and they had a few premature detonations during testing with the XM-25 prototypes, from what I’ve read. It takes work to get electronics to cooperate with explosives.

  • Jon

    What reason do you have to second guess the report? I don’t see anything about software, in fact I see the explanation right there. If the trigger is squeezed a little at the wrong time, the round is misaligned and the communication link, likely physical contacts, become misaligned.

    Software isn’t the cause for all faults, you know?

    • Andrew

      Dude – the s/w is responsible for the timing – whilst it’s the h/w that starts the process (pressing the trigger), it’s up to the s/w to ensure that this zero range error can’t happen since it’s SOFTWARE not h/w communicating to the round.

      From what’s being coming out about this thing, it’s sounds like there are a huge range of h/w and s/w issues

  • Lemming

    A very unfortunate accident, I’m glad the soldier who fired it is mostly unharmed.

  • Mike Knox

    How do they say “What the f***” in Korean?

    • SomeKorean

      It’s “ssibal” in Korean.

      • Seamus

        easily one of the better names ive seen on here haha well played sir

      • theRealKorean

        It’s actually pronounced/romanized as “shibal”…

  • jdun1911

    If this was a standard 40mm grenade the kid will be in pieces.

    I remember people arguing with me how airbursting a very very very underpowered grenade is better at killing than the 40mm. All these people bought into the marketing BS. You can’t cheat physic and storage space.

    You have to go full retard to exchange a rifleman for OICW.

    • Mike Knox

      You’ve really got mental issues don’t you: “All these people bought into the marketing BS. You can’t cheat physic and storage space”.

      A rifleman is a person and an OICW is an article of equipment. Dumbass..

      • jdun1911

        Mike Knox don’t post what you don’t understand. The OICW is platoon level system. In order to fit in the platoon it must replace something. So what it going to replace in a Platoon? Another rifleman. The squad who end up with the OICW is more screwed.

      • Mike Knox

        Do you even know what OICW stands for? Objective Individual Combat Weapon, both for the weapon program and article of equipment, not a unit level system.

        Putting this weapon in the platoon wound replace the 40mm with a 20mm along with two to three more while at least doubling their rifle grenade loadout. Surely not a disadvantage, just as much you don’t know that. You understand the sitting of the firearm in a military unit like you know physics, horribly..

      • jdun1911

        Ok lets call it the XM25 so you won’t get offended.

        The XM25 won’t replace a grenadier. Your platoon leader have to go full retard to replace the beloved 40mm for the useless 25mm that can’t kill. The platoon leader won’t replace any machinegunners with the XM25. Machinegunners are too important. The platoon leader might replace the DM but I doubt it in Afghanistan. What’s left? Oh the Rifleman.

        This issue have been discussed within the platoon community.

        Seriously if I were a Platoon leader, I’ll play the XM25 at the range. When it comes to killing people I’ll bring the real stuff.

      • Mike Knox

        Simply reading your replies makes me question your mental ability with technical matters like this. Just look at your composition, you’re using words typically seen in multiplayer chats. I’m comfortably assured your references may just be call of duty and battlefield videogame playtime.

        “useless 25mm that can’t kill”, tell that to the taliban or Iraqi insurgents. the XM25 even took over the entire fire team except for sharpshooters in repeated engagements in Afghanistan, that’s why the called it the punisher, because it fought back ambushes and harassing fire with little help.

        If the 25x40mm were good at blasting remote cars and mincing the loaded dummies, then it’s not a question how good they are at taking apart targets three at a time in combat..

      • W

        “Ok lets call it the XM25 so you won’t get offended.”

        You can call it whatever you want since the OICW is defunct. I was puzzled when you used OICW anyways since the program has been ditched for a decade now. the XM25 and K11 are different weapon systems anyways with a similar theory behind their purpose.

        “The XM25 won’t replace a grenadier. Your platoon leader have to go full retard to replace the beloved 40mm for the useless 25mm that can’t kill. The platoon leader won’t replace any machinegunners with the XM25. Machinegunners are too important. The platoon leader might replace the DM but I doubt it in Afghanistan. What’s left? Oh the Rifleman.”

        It is very possible for the XM25 to replace conventional grenade launchers (like the M203 or M320) since it is a forward leap in small arms technology in my opinion. It provides true counter defilade capability (It is called the Counter Defilade Target Engagement, or CDTE, after all) that relies on smart munitions rather than trajectory and blast radius alone to counter dug in infantrymen. Regardless of what you may have heard, the XM25 is performing exceptionally well in Afghanistan, where it is credited as being particularly useful against machine gun nests (like what grenade launchers are supposed to be good for). If it is more accurate, effective, and consistent than the UBGL, then so be it. Technology evolves. And the XM25 is not intended to replace machine gunners or designated marksman, the CDTE, weighing at 14 lbs, is supposed to compliment existing weapons and give the infantry platoon a capability it never had before.

        Im with Mike; this weapon system has the capability of increasing a infantry platoon’s grenade load out, which coupled with increased accuracy and effectiveness, is a no brainer. Of course, the problem is not the weapons system or technology, it is rampant luddism.

        “This issue have been discussed within the platoon community.”

        Which issue? The XM25 is not supposed to replace anything. Only compliment.

        “Seriously if I were a Platoon leader, I’ll play the XM25 at the range. When it comes to killing people I’ll bring the real stuff.”

        Hmmmm, the XM25 seems to work well in afghanistan.

    • Jeff

      The move to smaller diameter airbursting grenades is out of a concern for collateral damage. Between the improved accuracy, the much greater range, and the range setting this is all about putting a grenade where you want it. The Korean design was born out of their desire to mirror our military and sell these to the US. The “need” for the design was born out of the fact that in the not to distant past, soldiers were put in urban environments and told not to use their 40mm grenades if they could help it. This grenade, the oicw, and the xm-25, are grenades that can be used anywhere a normal rifle is used at the range a rifle fires, with only the most basic concern to collateral damage.

      • jdun1911

        Pure marketing BS.

        If I’m launching grenades on my enemies I intend to kill them, all of them. It is not my intention to piss them off so they can come over and shove it down my ass.

        This system suck because it doesn’t kill anyone.

      • Mike Knox

        Who died and made you expert of all firearms?

  • bbmg

    “the poor lethality of the small 20mm grenades”

    I think that is unfair on the projectile.

    Some extensive footage of the Denel PAW-20 testing: http://www.youtube.com/watch?v=xsBEQ-Pulvc

    It’s not the same 20mm round but performance should be on par with the shells fired by the K11, and it’s clear that it causes extensive damage.

    Had the same shell exploded outside the confines of the barrel at the same distance from the hapless shooter’s head, I seriously doubt he would be alive.

    • Nater

      Shooting at barrels really isn’t a good indicator of performance. It looks cool, but it doesn’t tell you much. The kill radius of a 40mm grenade is 5m. Anything beyond that is going to most likely live. They might take frag, and they’re definitely going to have blast injuries, but more than likely they’ll survive and fairly likely that they’ll be able to fight if they have to.

      A 20mm grenade would be significantly less effective. These things probably have a kill radius of a meter or two. The old OICW originally used 20mm ammunition, they then went to 25mm and it is still debatable if this is enough punch. The Marines are having none of the 25mm talk, they want an XM25-type weapon that fires 40mm grenades.

      • Jean Luc Picard

        Actually there is 40 mm grenades with programmable rounds, ST kinetics manufacture them and I believe they aren’t alone to do so.

        As for OICW projects there is various rifles aside of the XM 29 with higher caliber like the metal storm.

        There is also systems that allow some weapons to be compatible with those programmable grenades through upgrades.

        The only thing that people needs is to adapt them into a weapon like the china lake or the miklor MGL and then you have a weapon that can outclass the XM 25 in the matter of fire power.

        However I wonder if we don’t loose any kind of flexibility.

      • bbmg

        There’s no point in arguing that a 20mm grenade is more destructive than a 40mm one, no doubt about that. What the 20mm grenade has though is a flatter trajectory, better ballistic coefficient and shorter time of flight, making it much more likely to strike its intended target, therefore the smaller blast radius is compensated for.

        You also have the ability to deliver multiple rounds on target in rapid succession, something which a typical 40mm grenade launcher cannot.

        What I would like to see is a 40mm grenade with a similar explosive weight to current rounds, but with a lot more attention given to aerodynamics, perhaps something saboted similar to the M830A1 tank round:


        This would achieve a flatter trajectory and shorter flight time from a 40mm launcher without sacrificing shell weight or increasing recoil.

      • jdun1911


        If it can’t kill it useless. If I get a direct hit with the grenade I expect the person to die.

        The 20mm went KB! point blank and they kid probably got out of the hospital the next day.

      • Nater

        It was contained in the high strength steel of a weapon barrel. Not exactly the same thing as one hitting the ground in front of you.

      • Mike Knox

        Do you know anything about the 20mm caliber? I’m sure you don’t because you assume it’s difficult for it to kill one person while it’s already been used to tear into aircraft, equipment and even half a squad at once.

        Unless any of you read, the round went off in the barrel and most of the blast was absorbed by the deforming titanium barrel while the rest went either ends out the muzzle and into the breech. More went out the former than the latter.

        And you assume you’re good at physics. Now that’s BS..

      • Mike Knox

        ^above addressed to jdun1911

      • W

        “If it can’t kill it useless. If I get a direct hit with the grenade I expect the person to die.”

        This wasn’t a case of a “direct hit”. It was a KB that was largely absorbed by the titanium of the barrel. The fact that the operator didn’t die is a testimony of the quality of materials and engineering of the weapon system.

        “The 20mm went KB! point blank and they kid probably got out of the hospital the next day”

        Like i said before, there is a difference between being hit by a 20mm that was allowed to acquire respectable velocity out of the barrel to a KB that occurs when the round is still inside the rifle.

      • jdun1911

        Mike Knox,

        Let me put it to you and everybody that is reading. We can all agree that grenade should kill at 0m right?

        If a 40mm that KB! inside the Mk19 it will kill the two person that man it. It’s not my opinion it’s a fact.

        If a person put his helmet and his body on a live hand grenade. The hand grenade will kill him but likely saved his friends. That’s not my opinion that a fact.

        A .50 cal (12.7) that KB! has a high chance of killing the shooter.

        If a 20mm go off inside a K-11 you’ll survive. What that tell you? It’s not lethal even at point blank range.

        We can all agree that the 40mm is bigger than the 20mm. We can all agree more space percentage are given for lethality in the 40mm than the 20mm. Why? The electronic inside the 20mm and 25mm take a crap load of space. That means less toward killing.

        Both the 20mm and 25mm are too small and isn’t design to kill your enemies. It design to piss them off so they can come over and shove it up your ass. I can assure you that will be painful.

      • jdun1911


        Do you think he will survive if a 40mm went off inside titanium barrel. It funny to see so many people to tried to rationalize this.

      • W

        Jdun, mk 19s kaboom and soldiers remain unharmed…even with HEDP. How do you rationalize that?

      • W

        and I suppose the XM25 CDTE earned the nickname “the Punisher” because it was weak and anemic, having a propensity to encourage enemies to shove the launched round up the shooter’s ass LOL. If you were on the business end of a 25mm, it wouldn’t be the shooter getting ass raped…especially if yours was clinging to the bottom of a trench.

      • Mike Knox


        Hey dumbass, modern Rifle warheads and grenades have muzzle fuses that start a short distance outside the muzzle.

        Even in catastrophic failures, grenade fuses won’t go off and leave the warhead as a dud.

        Putting a helmet on a grenade to save people is a myth, it’ll either become a secondary projectile or cause more fragmentation.

        It’s already been documented in reports everywhere when catastrophic failures with .50 calibres cause lacerations and burns at the worst. In fact CFs almost always have the projectile leaving the barrel while user trauma are minors caused by component fragmentation and vent burns.

        I know you haven’t read the story because it clearly said the warhead went off partway into the barrel causing deformation and receiver splintering. CFs like that have the blast mostly leaving the muzzle.

        Unless you’re still using blunt circuitry, Electronic Warhead fuses are chips smaller and thinner than the cartridge base, or even smaller than the primer themselves. In fact it’s the cheapest part of the round (just half a nickel) and barely five percent of the warhead mass, often just two hundredth.

        As a matter of fact, 20mm rifle grenade rounds are geometrically shaped to detonate sending fragmentation elliptically parallel to it’s trajectory and blast pressures in a belt. The 40mm on the other hand just propagates the blast hemispherically after hitting a solid target.

        I’m sure you’re just masquerading your weak guesses as a fact knowing how ignorant you are on the mechanics of this issue. Replies on other threads even show how disagreeable your firearms and physics knowledge is..

      • Mike Knox

        Another thing, I’ve already seen a 40mm CF on an M16’s M203, it left the tube sprawled out like a busted banana but everything behind the breech was left intact. The shooter only suffered skinned knuckles from a rim. It was a from repeated strike on the primer with a misaligned tube. The Warhead was deactivated..

      • Jean Luc Picard

        I believe that part of the explosion is canalized through the barrel where the energy can escape more easily, but it wasn’t enough to prenvent the weapon to blow, but I believe that some of the shrapnel went through the barrel.
        I’m not an expert though so I might be wrong about this.
        But I think that can explain why he survived the explosion, no ?

      • W

        “Hey dumbass, modern Rifle warheads and grenades have muzzle fuses that start a short distance outside the muzzle.

        Even in catastrophic failures, grenade fuses won’t go off and leave the warhead as a dud.”

        damn you Mike!!! I wanted jdun to answer my question! LMFAO!!!!

      • W

        here, jdun, pay attention to the video. Itll demonstrate what mike said about the “belt” blast pressure.

  • D

    Complexity breeds failure points. The more complex something is, by default, the more likely it is to fail. The very first thing i thought when i saw these was to think “A programmable explosive is one apt to blow up at the wrong time.”

    That said, I do think this adds something valuable to the soldier’s arsenal, and something useful to have, especially in coming years. Every innovation brings some risk.

    For the record, i would have it so the system literally could not arm until it spun, via a physical blockage of some kind. I’d rather have a dud down range then a blowup in my hand.

  • Nater

    I’m a computer/tech guy and I always cringe when people start talking about integrating that sort of technology to firearms. You’re adding another order of magnitude worth of problems when you strap software onto a gun. Hardware? Really not a big deal, it’s easy to make electronics tough enough to withstand long term use on a firearm.

    On the other hand, software bugs are the last thing you want on a weapon. It’s pretty easy to find a bug report for any piece of F/OSS software you might (re: should) be using. It’s a real eye opener.

    We’re going to see more and more problems with software in the things we use every day. I find it pretty incredible that we haven’t seen hosts of software issues with automobiles yet, but maybe they’re happening. I haven’t been an auto tech for ten years and the complexity of the software running today’s cars has increased dramatically in that time frame.

    • Komrad

      Wasn’t the problem that Toyotas had with uncontrollable acceleration software linked?

      • EsEf

        Nope – it was “silly users”, that caused most of Toyota’s problems. But I’ve suffered a real nasty software-bug on a brand new BMW. Nearly drove me into the rough side of a motorway.

        Beside this I’ve seen lots of software related failure on cars. NOT funny!

        The more computers and software you have in vehicles or guns the more dangerous it get’s.

    • W

      can you imagine if “smart guns” with a safety bracelet were mainstream? that idea alone made me sleep fitfully at night.

  • NickB

    The shooter may not have suffered life threatening injures, but his underwear sure as hell did.

  • Chucky

    Steve, I don’t think these 20mm’s have an inertial (spin) safety like the 40mm’s do. For one thing that safety device on a 40mm already eats up 1/3 the space of the projectile. Even if one were micronized to fit a 20mm, it would probably end up having less charge than a 12 gauge.

  • Hrachya Hayrapetyan

    They’d better convert the grenade launcher into a 12 gauge shotgun (half joking half serious).

    • Mike Knox

      Part of the idea for the H&K CAWS along with the G11, but that blew in a German way..

  • Lance

    More reasons I wouldn’t want a auto grenade launcher on my weapon. Overall reason like this, as well as others is why OICW died here in the US.

    • Sian

      The K11 grenade launcher is a bolt-action repeater, not semi automatic.

  • Jim March

    Somebody probably left a fan on.

  • I’ve skimmed through most of the comments and haven’t seen this mentioned yet. But this grenade isn’t spin armed. It is electronically armed based upon a trigger pull that is short of the trigger pull that sends the round down range. So the soldier pulled the slack up on the trigger, waited a couple seconds. During those couple of seconds, the grenade was armed. Then when he completed the trigger pull and the round fired, it also detonated. At least, that is how I read the article.

    As for my comment, wow, that is all kinds of dumb.

  • Jean Luc Picard

    There is anyway fails with much simpler and battle proven weapons like this one http://www.youtube.com/watch?v=tkE-cCJ–Cc. those bad things just can happen :/

  • Big Daddy

    1- It’s bulky and would be difficult to maneuver with as an infantrymen. When hitting the dirt, trying to find cover and concealment, using it as a true rifle and so on I think it would be much worse than the M203 I carried.

    2- The 20mm round does not have enough explosive force or shrapnel to create a good killing effect. It may be more precise but I wonder how well it does at actually killing combatants. It looks more like it would cause slight wounds if the combatant were covered with a quality helmet and body armor. Maybe some slight flesh wounds if that. The 40mm grenade is a killer.

    3- You are a target for a sniper, after the officer or NCO I would be pointing my weapon toward YOU.

    4- It would be cheaper and in reality much easier in terms of deciding who would carry the weapon in the squad if it were separate units. You might as well buy the Neopup and put the advanced electronics on it, that would be much cheaper. I find this Ripley gun thing to be ridiculous. The US Army figured it out by spending billions of US tax paper money.

    5- The US army is closer with the XM-25 although the cost is beyond what should even be considered. The Marines have a better idea by saying make it 40mm. It should be a separate weapon and more of an anti-material rifle like the old Barrett XM-109 with the ability to fire on infantry too. It would be like having some heavy fire like a M2 50 cal or MK19 40mm AGL but carried by infantry platoons. That and the M32 would provide small infantry units great firepower and overlapping weapon systems. This would be cheaper, the advanced electronics could be added to both weapons when the bugs are worked out.

    6- This Sci-Fi Ripley gun mentality has to go. It looks great in movies but the reality of being an infantry soldier dictates that weapon’s makers think about that reality and design weapons to kill the enemy not get our soldiers killed or be targets themselves. That goes for any country, South Korea, China, Russia, the US or any other country, it should be their main thought for their war fighters.

  • Ian

    Cool, it did the same thing that the XM29 OICW did in American trials. Koreans always copying the Germans…

  • Domestic Squirrel

    its OS got hacked by anonymous