What do you guys make of this Kaboom?

Discussion in 'Gunsmithing' started by atblis, Feb 17, 2020.

  1. atblis

    atblis

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    Glock 22C with a Lone Wolf 357 Sig barrel (otherwise stock)

    [​IMG]
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  2. sourdough44

    sourdough44

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    Factory or reloads??
     
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  3. Variable556

    Variable556

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    and to add to sourdough44’s question: how many times was that particular piece of brass reloaded?

    edited to add— “atblis”: Can you provide more details please? Way more info is needed to make any reasonable guesses.
     
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  4. Fatelvis

    Fatelvis

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    Looking at the primer's brass flow, it's apparent it was definitely an over pressured round. Not only cratered, but full flow into the breechface. If I had to guess, I would say either a massive (or wrong powder) overcharge. Firing out of battery wouldn't crater a primer like that.
     
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  5. atblis

    atblis

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    What I am trying to figure out is how does the neck end up like that?
     
  6. DevinBreeding

    DevinBreeding

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    Looks like it expanded and formed perfectly to the unsupported feed area of the chamber.

    I bet if you did a plunk test on 357sig Barrel that would be where brass is visible.
     
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  7. Mr Meeseeks

    Mr Meeseeks

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    It looks like the KB happened out of battery. Neck pushed forward and the rear is ballooned out 360*. It seems this type of ballooning would be more likely in the 357 Sig due to its fully supported chamber. A .40 S&W on the other hand, shoots all the hot gases directly down the ramp/ unsupported area.

    All things being equal, it should be harder to KB a Sig, but it might be more ‘exciting’ when it does happen. What happened to the pistol/ barrel? Was the brass stuck in the chamber? Got any pics?

    ETA, just saw it was an LWD barrel. Would love to see a loaded round in the chamber of the barrel, assuming it’s still intact. More info on the bullet, COAL, powder, etc would be great too.
     
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  8. Variable556

    Variable556

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    Agreed. Without further info to go on, it does indeed look like it fired out of battery (OOB). Since no further info has been revealed, I’ll take a SWAG at it: Cartridge was fired while the pistol was OOB, and upon ignition the shoulder was pushed forward (#3), the base of the case ballooned out where it was unsupported (#2), and you can see how it was indexed by the ramp impression (#1). The case failed at the extractor groove starting at the bottom (ramp) and finally tore the base loose on the top at the exact opposite side leaving a hinge mark (#4).

    2173D13C-11BF-4F5A-BCB1-BD7424C25B07.jpeg

    Atblis: Is there a reason why you aren’t providing any further info? Your pistol/ammo? Reload? Load data? There’s a huge amount of missing info...
     
  9. Fatelvis

    Fatelvis

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    A cartridge fired out of battery wouldn't have the extreme primer flow, present here.
     
  10. atblis

    atblis

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    I'll post some details when I get to a real computer. I am leaning towards not an OOB for a couple reasons.
     
  11. ThomasM4

    ThomasM4

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    I dont mess much with 357 sig. But it does look like the shoulder is pushed forward I would have to compare it to a normal sig brass though.
     
  12. atblis

    atblis

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    Handload yes. Not a new load. Have a few hundred fired mostly through a different gun though. 10 gr of Longshot behind a 90 gr JHP. Unknown number of reloads on that case, but I don't see any indications that it was a well used case. Kinda hard to tell at this point. I hand sort and inspect my cases.

    Regarding damage to gun... Slide and barrel are intact. Extractor gone. Mag release broken. Frame cracked on right side next to locking block. Trigger plastic part is broken.

    Regarding case support, feed ramp has basically no intrusion. The chamber does have a chamfer all the way around. It's bordering on rifle like support IMO.

    The case might have simply failed. I say this because if you look at the amount of material attaching the rim to the body in the web, it looks mighty thin IMO. I am going to section some cases out of curiosity. Perhaps pressure was in excess of SAAMI, I don't know... I would expect the primer to be flattened more, and it doesn't look flattened at all. Reading pressure from primers is problematic IMO. Yes, it did flow into the firing pin channel, but that isn't unusual IMO. Looking at other fired cases, the primer gets swiped and flattened on ejection, which may make them look less raised. I don't think this case got a chance to be ejected (LoL).

    I keep coming back to the neck being blown out. I see two options, it either did in fact fire out of battery, or in the process of failing, the case was pulled out of the chamber while under pressure. I keep going back and forth on this one because it really does look like it fired out of battery. I was thinking that the marks on the neck were the result of being drug back in the chamber under pressure, but they match the marks on a freshly sized case. My sizer neck is scored from poor lube (need a new one).

    Geese, so I am really leaning towards firing out of battery. The argument that if it was OOB, it wouldn't have made pressure is interesting. I see the merit in that the case would act as a fuse failing before pressure could peak high. I believe this would happen if the case wall were exposed. However, with the support as good as it is on this barrel, even a good bit out of battery would be about like the feed ramp intrusion typical on the 40s and such.

    Some pictures for your consideration. Keep in mind that the picture at the end, is not the barrel that's in this gun. I couldn't even get the marker in to mark the side of the case.
     
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  13. atblis

    atblis

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    [​IMG]
    [​IMG]
    [​IMG]

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    [​IMG]

    Here are some other fired cases during load workup for primer comparison. Notice that they're smeared.

    [​IMG]

    Keep in mind this is not the same gun. The one in question actually has less feed ramp intrusion on the 357 SIG.

    [​IMG]
     
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  14. atblis

    atblis

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    nvm
     
    Last edited: Feb 20, 2020
  15. Fatelvis

    Fatelvis

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    To me, The primers in the 9 fired cases pic definitely look like overpressured loads. I never see primer flow like that in any of the 9 cartridges I load for.
     
  16. Glockman4

    Glockman4

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    Damn. How does the gun look?
     
  17. atblis

    atblis

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  18. atblis

    atblis

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    Can you guys see that last picture?
     
  19. atblis

    atblis

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    I am trying to post a picture of the entire frame, but I think this site won't let me because it's a gun and this site deems it inappropriate. What the heck? That's the message it gives. LoL

    "Your content can not be submitted. This is likely because your content is spam-like or contains inappropriate elements. Please change your content or try again later. If you still have problems, please contact an administrator."

    Here's the link. Let me know if it works

    https://photos.google.com/album/AF1.../AF1QipMMfa2OFxnXAtkSN3yPydBahpUnyo11n-7ua1Pe
     
  20. ReaPer105

    ReaPer105

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    Link doesn't work