Name That Failure (Based on a Picture)

It’s almost impossible to scroll past an image on social media depicting some sort of firearms-related failure without stopping to make your own diagnosis. Even more entertaining is scrolling through the comments, because the web-based opinions tend to range from possible to preposterous, and everything in between. Not to say it’s simple to diagnose something based on a picture alone. And of course that’s exactly what I’m giving you guys a chance to do: make your own diagnosis based on the picture and the bit of information I was able to obtain.

The round pictured below was apparently fired through an HK53. According to the original poster the rifle was freshly cleaned the morning he went out shooting. He fired “some” steel cases but said the majority of rounds fired were Federal Lake City 5.56 NATO 62 grain FMJ – the ever-popular XM855 Green Tip. As for quantity of rounds fired prior to the failure the original poster estimated it at a “few hundred.” Regarding removal after the failure, in his own words: “Had to beat the bolt back with a block and hammer to remove the casing.” He then fired approximately one-third of another magazine – magazine size unknown – before the rifle stopped feeding entirely.

While it does look like a pretty straightforward (obvious) problem, there are still multiple factors to consider. If the rifle really was clean and oiled immediately prior to shooting, if only a few steel cased rounds were fired – considering the whole picture as it was given does bring up questions. Of course, it is the internet, so assuming details are given with 100% accuracy and honesty tends to be pushing the constraints of logic a bit. With that in mind, take the details with a grain of salt and diagnose the failure.


TFB Staffer

TFB Staff, bringing you the latest gun news from around the world for a decade.


  • Casey

    The cartridge clearly spent too much time in a banana clip and decided to peel like one.

    • Shocked_and_Amazed✓ᵛᵉʳᶦᶠᶦᵉᵈ


  • Ambassador Vader

    I’ve seen over charging of reloads that will expand the case and lodge it in the barrel, combine that with the hk53 barrel flutes plus rough extraction will score the casing that way. I have never seen factory ammunition do this.

    • kzrkp

      it’s either this or the flute dimensions are wrong and it’s not supporting enough case.

  • Either the case was too soft, the pressure was too high, and/or the chamber flutes were cut too deep. As to the pressure issue, I wouldn’t rule out the possibility that the throat dimensions were cut to commercial .223 Remington specifications and not 5.56mm NATO. A true factory HK53 might not have chamber dimension issues, but I wouldn’t put it past some of the clone manufacturers.

    • Ambassador Vader

      I agree with the clone mfg statement. The throat cut difference I could see but i think there would be more scaring on the throat. definitely a fluting dimension issue. Maybe this is a high tooling number barrel and the clone mfg don’t change out or service their tooling as often as they should, which lead to a slightly under cut fluting.

    • Mmmtacos

      One look at the picture and it quite clearly came from an old HK roller-lock rifle. Can’t have those striations otherwise without the chamber-flutes. I’ll go with the simple explanation: too much pressure caused by a hot load.

      • I think Daniel is talking about HK53/33 clones, as opposed to HK-made examples.

        • Right, most HK53 in public circulation are actually aftermarket conversions or clones.

        • Mmmtacos

          Too little to late: but I did mean to type “style” somewhere in there. I know reproductions are far more prevalent than an actual HK model.

    • ostiariusalpha

      If there was some bullet setback is another possibility for the pressure issue. Though I wouldn’t generally imagine that happening with a good crimp, I have had badly seated bullets in factory rounds before.

  • Major Tom

    It’s God’s way of saying don’t buy H & K. /silly

    • Mystick

      “Well…. there’s your problem right there! It says HK!”

    • Barrett West

      Hell, it ruins the brass either way.

      • iksnilol

        IIRC it is mostly due to being banged against the case deflector or something. I remember there was a thingy you could buy that helped the brass not get banged up. It went on the side of the rifle, close to the ejection port.

      • MichaelZWilliamson

        But it throws the brass at the enemy, sort of like a point after touchdown.

        • Or a Vz52 pistol. Which has the advantage of hitting the enemy sneaking up on your right flank and removing his teeth.

  • randomswede

    Maintenance -> Normal use with factory ammo N(200,999) rounds -> Failure to extract -> Forced extraction -> Normal use with factory ammo N(3,27) rounds -> Failure to feed -> No further action

    Assuming the last action taken caused the problem that followed;
    – The maintenance caused the failure to extract
    – The forced extraction hooped the feeding

    Bad oil?

    • ChierDuChien

      Sand/dirt on the ammo started lodging in the flutes ?

      • randomswede

        Causing additional friction?

        I can’t imagine that would deform the shell casing like we see in the picture.


    5.56 in a 300 blackout.


      &lots of foreward assist, pound it back out with a cleaning rod and voila

    • MichaelinPA

      This is what I am thinking as well!

  • DIR911911 .


  • borekfk

    I guess he didn’t incant the right spells for his Kraut space magic.

    • A.WChuck

      I laughed. I’m half Kraut, the non-magical half.

  • That’s what happens when Freddy Kruger forgets to de-glove before loading his magazines.

    • Swarf

      Freddy Kruger is apparently a lot smaller than I thought.

  • felix

    Should have this going daily or something then turn it into a raff. No ttag tho

    • Katie A

      I can keep it going if you guys like, I have a steady supply from readers and gun groups. It would be great if you all emailed me the occasional failure pictures, too.

  • HH

    I’ve had similar appearance with my MP5k (factory gun…well converted SP89…but either way not a clone)…and it was exactly what other posters have said…too hot of reloads. It grooved the heck out of the brass. Was that batch of reloads only.

    So key info needed is :
    A. Clone build or factory gun?
    B. Reload ammo or not (It says he was firing Federal LC some but didnt explicitly state that the round shown in the pic was that)

  • FightFireJay

    If the brass wasn’t annealed correctly, it might fail like that in an HK. But in any other 5.56 it would probably result in a split neck.

  • Jay

    Normal operation in a g3. :p

  • Twilight sparkle

    It looks like something caused a pressure issue, being loaded with the wrong would be my guess, I feel like ammo may have been reloads. The round sticking was probably caused because too much pressure expanded the brass into the flutes of the chamber which are ironically supposed to help extraction.

  • Gabe

    This explains it.

    • Mystick


      • Sulaco

        Looks like the Ambassador Lon do’s son on Babylon Five.

        • Mystick

          “Quickly, we must kill this bug before it develops language skills!”

  • SirOliverHumperdink

    Not impossible, as not everyone uses stupid ‘social’ media.

  • Mystick

    Based on the picture at the top, the failure was in running out of money to buy more ammo.

  • I’m going with an over pressured cartridge in a fluted chamber

  • iksnilol

    I am gonna be boring and guess to hot round.

  • Nick

    Excessive pressure + Fluted Chamber result in this.

    The question is however, what caused the excessive pressure. Perhaps an unnoticed barrel obstruction or maybe sheer bad luck in getting a bad cartridge from the factory.

    Of course, we can’t rule out the possibility he hand loaded this and doesn’t want to say so. After all, almost every manufacturer says hand loads void the warranty.

  • Will Donoho

    It’s my rifle. New build off of a Malaysian parts kit from APEX. All factory ammo. (I don’t reload). Was using 40rd aluminum mags. About 30 rounds of steel through it. About 10 brass 55gr rounds and the rest was lake city 62gr. Best guess on lake city round count is around 250.
    Cleaned it this evening and there are strips of brass stuck in some of the chamber flutes.

    • US case brass is softer than what the Krauts designed those things around.

      • Will Donoho

        so would you shoot steel or European brass?

        • Steel without hesitation. Brass cased ammo from a factory that produces brass cased ammo in that caliber for that country’s delayed blowback rifle. (Although, keep in mind that a lot of the Russian/former USSR steel case *also* uses harder bullet jackets that roughly double barrel wear per round over softer jackets. Not an issue until *thousands* of rounds have been fired, but if you’re a high volume shooter and have a rifle that isn’t easy to rebarrel, it might be a consideration – with something as easy to rebarrel as, say, an AR, it’s a still cheaper to replace barrels more often and save money on ammo. HK designs are harder to rebarrel, but I don’t have the data to quantify the difference.)

          Delayed blowback rifles are more sensitive to cases being too soft than most other action types, due to the way they function.

          But all delayed blowback guns I’ve seen eat almost any steel cased ammo like a fat kid locked in a candy store.

  • Mr Silly

    Case deformed to fit chamber. Arguably shell had too much propellant.

  • Dr. Longfellow Buchenrad

    Im going to venture to say it was because he loaded the round in the magazine with the bullet toward the front. We all know HKs feed the other way.

  • M

    Round detonated without brass being fully supported. Maybe the locking piece is not enough. May not be apparent with lighter loads (steel case tend to be 55gr) but presented itself when 62gr brass was fired

  • Aaron E

    The failure with the first picture is that someone has not been keeping up with their reloading, and there is WAY TOO MUCH brass sitting around lonely and neglected.

  • dltaylor51

    It looks like the chamber is flame cut from hot gases getting between the outside of the case and inside of chamber due to bad metallurgy,barrel is junk get a new one and have it mag tested and UT’d before installing.

  • Doom

    maybe the brass was very thin or weak for some reason or another and/ or too much powder and the chamber fluting gave it space to expand out into and it split like crazy?

  • Old Vet

    With the striations going on into the neck of the round I would guess a slight out of battery ignition??

  • BigR

    Could it have been smaller case, like a 5.56 round, that somehow was accidentally fired in a larger caliber rifle? I’m no gunsmith, just saying, those look like land and groove marks on the case.

  • Mike11C

    I’m going to blame it on the lacquer on the steel case rounds melting and sticking to the inside of the chamber. Then after further heating up the chamber with the brass cased rounds, the lacquer finally fused one of the cartridges to the chamber locking it up. I don’t trust that steel cased stuff. I especially wouldn’t shoot it in a H&K because of the fluted chamber.