redcon1
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without knowing anything else, I'd say it looks like a 6:00 blow out from a not fully supported chamber and a high pressure situation problem inside the case.
Reloading Oopsie...
- Thread starter ZeviB
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LiveLife
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Notice rounded edges of primer cup ... to me indicates case base blew out at 6 O'Clock position before flattening the primer cup. My guess is case base was overly expanded/thinned/damaged/weakened to experience case wall failure/rupture which could happen with below SAAMI max pressures.
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In this case I do, as I'm the original owner.
I think 3rd Gen - Ser.# EZW... Bullet was FMJ.
fxvr5
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Bad case / overcharge / unsupported.
If it was an out of battery round, the firing pin hit would be off center.
https://www.ssusa.org/articles/2018/8/14/firing-out-of-battery/
If it was an out of battery round, the firing pin hit would be off center.
https://www.ssusa.org/articles/2018/8/14/firing-out-of-battery/
The 6:00 theory is supported by (1) the orientation of the blowout that is in line with he firing pin (not perpendicular to it), and (2) the fact that the magazine was forced out.
I forgot to mention this last bit until this 6:00 thing came up, making me envision the blowout pressure going straight down into the magazine. At the time I thought that I accidentally pressed the eject button.
I forgot to mention this last bit until this 6:00 thing came up, making me envision the blowout pressure going straight down into the magazine. At the time I thought that I accidentally pressed the eject button.
With nearly every possible cause already posted. I'm gonna go with WAG (wild a$$ guess); a Super Nova caused a magnetic infarction in the atmosphere and the firing pin became magnetized and jumped the bolt face during feeding and ignited the primer prior to proper chambering, coupled with a case made from a third world import, inferior brass alloy, all occurring when the Earth was in a microsecond rotation pause. But also a "Killer Load", purposely snuck into a box of ammo by an Anti-Gun terrorist working for the Radial Left, New Age Activists...
Or chalk it up as a one in a billion combination of problems aka; a "Perfect Storm" cartridge...
Or chalk it up as a one in a billion combination of problems aka; a "Perfect Storm" cartridge...
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Could be, or the pressure was released early enough not to flatten the prier, dunno.Notice rounded edges of primer cup ... to me indicates case base blew out at 6 O'Clock position before flattening the primer cup. My guess is case base was overly expanded/thinned/damaged/weakened to experience case wall failure/rupture which could happen with below SAAMI max pressures.
I have no idea what caused this rupture, I' thinking bad case, not enough room for
a double charge of W-231. The case head just simply separated from the body.
lordpaxman
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@ZeviB, that looks exactly what can happen with Titegroup, a very fast powder, a 115gr lead RN, .1gr over the starting charge, but loaded .020” shorter than specified in Hodgdon’s data. Fired out of a DW pointman. Not every case blew out, and there were no pressure signs evident in prior firings. Neck tension was high, no setback, just a bit more pressure than the case could stand.
These days, you have add Computer in there.
jmorris
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The loose nut behind the wheel, you are correct.
Bat Rastard
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I have had bad similar occurrences.
My fix was sorting all loads in a case gage. The case gage would detect an occasional tiny Crack the base of the case. Those cases would chamber and pass a plunk test in the barrel. I no longer spot check a few random samples.
I run each case through the case gage. I have not had a case blowout since.
The extra inspection time is a cost of using range brass.
My fix was sorting all loads in a case gage. The case gage would detect an occasional tiny Crack the base of the case. Those cases would chamber and pass a plunk test in the barrel. I no longer spot check a few random samples.
I run each case through the case gage. I have not had a case blowout since.
The extra inspection time is a cost of using range brass.
PWC
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Glad oopsi wasn't a ouchie
JJFitch
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Classic result of OVERCHARGE/OVERPRESSURE! Period.
Prove to me that any modern handgun will fire out of battery!
I have seen too many of those "blow outs" in the last 50 years as an instructor, Range Master and Competitive shooter. In most cases surrounding shooters will notice an extra loud bang. Some go un-noticed because the gun fires and functions normally!
Reloaders are in denial that they could "overcharge" or improperly seat bullets in their reloads!
Smiles,
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JJFitch
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Master Blaster
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Simplest answer is an overload. I am sure glock knows how to make 9mm handguns and barrels for them. The unsupported thing is tiresome. Some of us have been reloading for our glocks for over 20 years and in 40,000 or so reloaded rounds never once seen a glock belly on a piece of our brass.
I found this brass at the range while I was picking up brass, it wasn't something out of my gun.
I wonder if the shooter knows how close they came to blowing up their gun or there hands. It looks to be as about as close as you can come without having it go boom.
It looks to have been fired from a 9mm AR from the extractor marks, but it was over pressured.
I wonder if the shooter knows how close they came to blowing up their gun or there hands. It looks to be as about as close as you can come without having it go boom.
It looks to have been fired from a 9mm AR from the extractor marks, but it was over pressured.
GeoDudeFlorida
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Wholly smokes! OOB, overcharge, cleaning media in the primer cup, over-length firing pin... lots of things could have caused that but it was pretty obviously WAY over pressure at the time it went.
LiveLife
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Yes to Pistol Caliber Carbine and not necessarily to over pressure.
That muffin case base is result of bolt/buffer moving away from chamber prematurely and expansion of brass can happen with below max load data/standard chamber pressures.
If that's the case, solution is to increase buffer/bolt combined weight to 19-22 oz (Often done with using heavier buffer like H3 instead of H1 with 9mm bolt weighing around 15 oz) so buffer/bolt contact dwell time with chamber is long enough before moving back - https://www.thehighroad.org/index.p...es-and-what-parts-did-you-use-and-why.825314/
- H1 buffer weighs 3.8 oz
- H2 buffer weighs 4.6 oz
- H3 buffer weighs 5.4 oz
- H2 buffer weighs 4.6 oz
- H3 buffer weighs 5.4 oz
I don't know what you wrote but it sure sound good!
Yes I know bolt and buffer workings but never fiddled with anything or dwell time.
RevolvingGarbage
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Maybe someone said it already, but a round which experiences set back upon chambering (or if it had been chambered before and wound up experiencing set back which went unnoticed) could also contribute to or cause this issue.
LiveLife
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With locked breech action firearms like AR/1911/Glocks, case is "locked in" until chamber pressure is reduced before case is extracted out of the chamber from gas pressure/recoil unlocking the lugs.I don't know what you wrote but it sure sound good!
Yes I know bolt and buffer workings but never fiddled with anything or dwell time.
With blow back action firearms like 22LR/fixed barrel 380Autos/Pistol Caliber Carbines, case is "held" against chamber only by spring tension on bolt/buffer and combined weight of bolt/buffer "delays/slows" case extraction out of chamber. Too light of bolt/buffer weight, case can be extracted before chamber pressure is reduced bulging the case base outside of chamber causing radial or "muffin" shaped expansion of brass.
In blowback action, after powder is ignited to case starting to move back is "dwell time". For carbine length recoil spring, 19-22 oz of combined bolt/buffer weight provides enough delayed or slowed movement of bolt/buffer to increase "dwell time" of case in contact with chamber and also reduces sharpness of recoil (There is gas pressure reduction from leakage around the case neck but won't discuss that aspect on this post). Lighter than 18 oz of combined bolt/buffer weight not only increases sharpness of recoil but decreases "dwell time" to aggravate out of battery expansion of case base.
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The only reason I said it was over charged was the brass case was crushed back into the extractor hole.
(red arrow)
I can see if it was not chambered all the way or if the bolt & carrier was too light, that it would push back early in the powder combustion causing a swell of the unsupported brass. But it looks like the bolt was plenty heavy enough to hold the case hard enough for the brass to crush into the extractor hole.
That just tells me overcharge & the shooter was just lucky it didn't go farther than that.
LiveLife
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I agree and there could have been multiple factors that could have caused the radial expansion of case base to include overcharging. Fortunately, malleability of brass contained the high pressure gas and did not result in case wall failure/rupture.
Regardless, shooter of that round should definitely do a root cause analysis of both firearm and ammunition if using reloads.
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