.243 KABOOM due to Left Over Cleaning Patch

A gunsmith received this bolt action .243 Win rifle that suffered a catastrophic malfunction due to a barrel obstruction. The apparent offending agent? A cleaning patch left in the firearm. I don’t know where the patch was left, in the barrel or the actual chamber. But either way, a simple patch appears to have done some absolutely devastating work to the action of this rifle. Or on the other hand, the owner was too embarrassed to say what was really the cause of the obstruction, and simply stated it as a cleaning patch. Whether true or not, that rifle would serve as an excellent fence post from now on.


As to the barrel being separated from the threads of the receiver, I’m not entirely sure what transpired. It appears that the barrel itself “jumped” the threads within the receiver. However it looks too clean and undisturbed for this to have happened. Instead, I think the gunsmith who examined the rifle pulled the barrel off, to get a better idea of what happened.


In addition, notice that the explosion seems to have been on the opposite side of the pressure hole that is drilled into many civilian bolt action rifles, this one on the left side. The purpose of this hole is supposed to direct pressure away from the chamber. So situations like this are at least somewhat avoided.


Infantry Marine, based in the Midwest. Specifically interested in small arms history, development, and usage within the MENA region and Central Asia. To that end, I run Silah Report, a website dedicated to analyzing small arms history and news out of MENA and Central Asia.

Please feel free to get in touch with me about something I can add to a post, an error I’ve made, or if you just want to talk guns. I can be reached at miles@tfb.tv


  • PK

    “that rifle would serve as an excellent fence post from now on.”

    Or, mounted appropriately and labeled, it would serve quite handily as a warning to the shooting public. Bore obstructions are taken far too lightly far too often.

    • BattleshipGrey

      There should be a museum where kB’d guns go as an example. All in one place. For now the internet will have to do. Maybe the kB museum should be called the Red room, kind of like HKs Grey Room. It’d be nice to have an updatable TFB page for all the kaboomed that come across.

      • Anonymoose
        • Porty1119


          • Ed Forney

            Looks like a huge cube of crushed firearms.

          • BraveNewWhirled

            It’s National Endowment for the Arts, taxpayer-funded propaganda piece, designed to inspire awe. The worshiper is part of the prop. YOU pay for this.

        • randomswede

          Glory be to the Murder /k/ube.

          • Anonymoose

            AVE ALEA NECIS!

          • Ambassador Vader

            All Hail the Murder /k/ube.

          • Richard Lutz

            We are the Borg. Resistance is futile.

          • CountryBoy

            Yeah, that’s what I thought of when seeing the photo too!

        • Ned Weatherby

          A Camo dude praying to the cube.

        • jonp

          It’s a mini Borg ship!!!

    • jonp

      Local gunshop, as many others do, has a number of rifles and pistol that have blown up on the wall behind the counter with an explanation below as to what happened. Good reminder especially for reloaders to be careful and methodical.

  • Tyler McCommon

    I have my doubts about the being a bore patch…..

  • Anonymoose

    >Or on the other hand, the owner was too embarrassed to say what was really the cause of the obstruction, and simply stated it as a cleaning patch.
    Yes, it must have been a condom. I can’t think of anything else that would be “embarrassing.”

    • JSmath

      A tiny dildo?

  • ExMachina1

    How would they determine this exactly? Surely the patch would still not be in the rifle…would it??

    • JesseL

      If it caused enough obstruction to blue up the gun, where do you think it would have gone?

      Odds are that the bullet and the patch that wedged it into the bore are both still there.

      • ExMachina1

        The obstruction causes over pressure but it does not have to occlude the bore for more than a millisecond. Plenty of photos around of “banana peel” shotgun barrels where the offending obstruction is long gone.

  • Rockchucker

    Reloads…. potentially an undercharged load on the preceding shot that only made it past the throat ( you guys have fun with that) followed by a properly charged load… ? = kB!

  • Joseph Goins

    “due to Left Over Cleaning Patch”

    Don’t you mean due to human error?

  • yukon cornelius

    Did the owner ask the gunsmith to fix it? Im no detective, but i’d say shes a goner!

  • JesseL

    The hole in the receiver isn’t for catastrophic failures, it’s for venting gas when a primer gets pierced out there’s a comparatively minor head separation.
    Without proper has direction and venting you can get gas traveling the length of the striker channel and escaping at the shooter’s eye.

  • Goody

    I’ve seen a shotgun peeled open at the muzzle from a stuck wad, and cotton isn’t actually compressible, so yeah I believe the story. There’s no excuse on a bolt action not to pull the bolt and inspect chamber/bore before getting started.

    Rifle is a tikka t3 varmint.

    • FriendOfJohnnyM

      Thanks- answered my above question.

  • jerry young

    I don’t know how everybody else cleans their guns but if I can’t locate a cleaning patch I’m using I find it and after I’m done cleaning I run a oiled patch through the barrel then a dry one to clean out any excess oil but I always ensure the patches I’ve used end up in the trash and the last thing I do is inspect the barrel with a bore light, unless this guy leaves an oiled patch in his barrel on purpose or doesn’t follow good cleaning habits I’d say something’s fishy about his story

    • Mikial

      So true!

  • Dan

    Please change the title of this post. There are some people that frequent this blog that may become confused and assume you are blaming the caliber for the failure. The rest of us won’t of course.

    • Ben Bushong

      Yeah, and some new gun people may actually believe that a cleaning patch did this, too…

      • Dan

        I was being a bit of a butthead in my post. I guess if this makes new gun people religiously check their bores for cleaning patches then that is a good thing?

  • Some Rabbit

    What was the gunsmith supposed to do with that, fix it?

    • FriendOfJohnnyM

      “A little glue and duct tape, and she be as good as new in no time!” heh heh.

  • Rimfire

    Curious as to the brand of rifle, did I miss it or not mentioned?

  • Dougscamo

    All these Kabooms are about to make me quit shooting….already giving me a terrible flinch….

  • diana pierce

    well well… here’s the diminutive .243 … this should have been the round for the AR from onset.

  • brian

    Someone give this guy a 556 AR15 and some 300 ammo! Hahaha

    Embarrassed? Like what? Using it as a dilly and not cleaning the turd burglar out of the barrel afterwards??? …..sheesh hahaha

  • Francisco Machado

    “Jumped the threads” – It’s amazing how much metal can distort under pressure, and this was obviously a lot of pressure. I work on motors – I read that an inside micrometer placed laterally in a cylinder bore and held by friction would fall out if the mechanic pressed on the ends of the engine block. Didn’t believe it, so tried it on a four cylinder (but placed a rag under the cylinder to catch it, anyway). It didn’t even take much pressure for the micrometer to drop. That barrel diameter was probably quite a bit larger for the instant of peak pressure.

    • Sunshine_Shooter

      I doubt it jumped the threads. More likely explanation is that it was unscrewed from the receiver before the pic was taken.

  • Stijn Van Damn

    The pressure hole is meant to direct pressure away from the chamber. False

    You can’t direct pressure away from the source. The 100000 psi or whatever won’t be redirected, eg “moved” from the chamber through the hole to somewhere else, it will just drop in the chamber. So it’s not redirecting away from the chamber it’s released from the chamber.

    The hole is there to redirect pressure away from the receiver, away from where the human is behind the rifle. The hole redirects the excess pressure coming “from” the chamber to a place where it can hopefully do no harm to the user..

    It’s coming from the chamber either way at that point, so instead of to the user it’s redirected through the hole , away from the user.

    • BraveNewWhirled

      As a Lefty that’s troubling. Chalk up another one for “Right Privilege”.

      • duh

        There is no left or right in anything I said. I said , “away from the user”.

      • Sunshine_Shooter

        That’s why my next bolt gun will be a left-handed one.

    • jonp

      your kinda splitting hairs on this one. Directing pressure away from the chamber and releasing it through a pressure hole is the same thing

      • Stijn Van Damn

        well no , it’s not the same thing, that’s the entire point.

        If nobody does anything, will the pressure remain in the chamber? no. It won’t, if it would, it’s would not be a kaboom in the first place.

        The pressure is already being released from the chamber IN the receiver (as opposed to releasing pressure through the barrel).

        So the redirection happens after it’s released from the chamber, and it’s being redirected away from the user. That’s the reason why they drilled the hole. Not to protect the chamber, but to protect the user.

  • Archie Montgomery

    One notes a rifle or shotgun will ‘split’ the barrel, down bore from the chamber if the bore is blocked not at the chamber (mud, snow, stuck bullet or cleaning patch?).

    A rifle or shotgun will explode at the chamber if the bore is blocked to prevent the bullet from moving or moving very far, not allowing the pressure in the chamber to vent (including expanding down the bore), overloading the chamber. Or, from an improperly loaded cartridge – an overload.

    In my experience and study, I find a single cleaning patch left in the bore should not cause this sort of detonation. Perhaps a wad of patches jamming the bullet in place.

    If possible, the remains should be checked to see what powder was used in the cartridge. It looks like – and obviously I wasn’t there and have NOT even handled the arm in question – looks like an extremely over loaded round. Mistaking a fast burning powder for the intended powder – for instance 4227 vice 4350.

    • Some Guy

      Yeah, I kinda doubt that this was due to bore obstruction, or at the very least there was probably some less than careful handloading involved.

      Factory ammo is usually well under the pressure at which the gun is proofed and a single cleaning patch isn’t likely to present much obstacle.

    • Mikial

      Good point. Doesn’t look like any barrel obstruction KB I’ve ever seen, and I’ve seen a few.

  • Larry

    You can not fix stupid! how long does it take to check out for chamber and bore on a handgun or rifle.

    • Dan

      Eventually life fixes stupid. Well when .gov stops meddling whenever they can.

      • Sunshine_Shooter

        If the stupid reproduces, then life has moved too slow. The Darwin Award is an ‘award’ for a reason.

    • CountryBoy

      Sure, just look down the muzzle when the thing doesn’t go off, right? /S

      You’re right. But I can tell you that the most obstinate customers in a gunsmith’s shop will be those who think they know it all, and eventually they’ll bring in something that proves just the opposite for repair. They’ll be very sheepish about what happened, and often try to hide the real issue, though we can usually tell exactly what happened.

  • Ned Weatherby

    I hate it when I leave cleaning supplies in the barrel.

  • Earl

    Accidents happen. All one can do is give diligence and due attention to safe gun handling practices when handling guns at the range or at the house.

  • Nashvone

    I guess I’m weird since I find the rifling in a barrel artistic but doesn’t everyone look down the bore before reassembling the firearm that was just cleaned?

  • FriendOfJohnnyM

    The gun looks like it’s made of pot metal. I’d like to know the brand and model of the gun. (so as to avoid buying one)

    • JoelM

      I’m not sure why you think it looks like low quality metal. That looks typical of a piece of forged steel that was fractured at high speed.

  • CavScout

    Bullshit. Wasn’t a bore patch. Probably something really stupid.