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Case failue

Posted: Fri Oct 05, 2012 4:04 pm
by Hakaman
An individual had a case failure today in his 45acp 1911. The energy blew downward through the magazine, also igniting the round below it. It jammed a few rounds down into the middle of the magazine, blew out the spring, and floor plate. The floor plate flew about 30 feet behind him. I also split one cocobolo grip plate in half, and left black soot marks on the shooter's hand. Amazingly, and thankfully, he was not injured. The case was blown where the feed ramp goes into the mouth of the barrel. The blow out started at the point where the case is at it's thinnest, going thicker toward the head. It was about 1/8" wide and extended about a third of the way around the brass. Makes me rethink using 45acp more then a few time, but also making sure the headspacing is correct.
H

Posted: Fri Oct 05, 2012 5:19 pm
by Bullseye
He may want to check his head spacing, that case should not have been unsupported. Otherwise check his cartridge overall length for the same reason.

R,
Bullseye

Posted: Fri Oct 05, 2012 5:39 pm
by Hakaman
When you say fully supported, do you mean the entire case? They way I understand the support in most semi autos is that the thick part of the case wall, closest to the mouth of course, is not supported.
H

Posted: Fri Oct 05, 2012 7:23 pm
by Medicine Hat
Ouch! If it was a re-load, he may want to check his loads and/or technique.
Or how many times the case was loaded.
Lots of maybe's here. What Bullseye said was my first thoughts also.
I have a .40 S/W that will sometimes make a very slight bulge at the base because of the feed ramp cutout, but not always, depending on my loads.
I have a 'push through' die that I use to iron out the bulges that works very well.
Just some thoughts

Posted: Fri Oct 05, 2012 9:18 pm
by Hakaman
These were reloads, and he mentioned they were reloaded several times. He wondered if he had double loaded it, but that can't be proven. I feel it was either a double load or over-used brass, and if I had to guess, it would be the later. You know there is alot of energy released to break the grip panel, detroy the magazine parts while casting the floor plate about 30 feet away.
H

Posted: Fri Oct 05, 2012 9:33 pm
by bigfatdave
I sure do like my solid aluminum grip panels.

And using quality ammunition.

Posted: Sat Oct 06, 2012 9:19 am
by Bullseye
"Fully supported" is about the barrel chamber walls surrounding the thinnest parts of the cartridge case walls. When a cartridge is not fully supported the case wall can rupture and leak hot gasses, as was the case in the pistol described. When you look at a .45 case installed in a chamber only the very back edge, near the bevel, is exposed. The case wall is thicker here to prevent case failure by normal detonation pressures. If the overall case length is stretched, a part of the case that is thinner will be exposed outside the barrel chamber and is highly susceptible to failure. A brass .45 case is pretty stout, and can take multiple reloadings. However one must keep an eye out for stretching of the case after numerous full length resizing because in a 1911 barrel, the head spacing is determined by the case mouth and overall case length. Stretched cases or improperly seated bullets can both cause case failures do to head spacing issues. The same can happen if someone messes with the bullet feed ramp and changes the ramp's depth into the chamber. A few thousandths of an inch can make all the difference here. Checking spent cases for "smiley" bulges are a sure sign of head spacing or chamber issues.

I have seen this type of failure many times and the results are almost identical to the ones you described earlier. Blown out magazine, blown grips, and a blackened hand are typical symptoms. So is an intense tingling, or stinging in the gripping hand for quite some time after the failure.

R,
Bullseye

Posted: Sat Oct 06, 2012 10:42 am
by Hakaman
Thanks for the info, BE, proper reloading techniques are mandatory.
I sure do like my solid aluminum grip panels.

And using quality ammunition.
Interesting thought BFD, do you think the aluminum panels would hold up in most cases?
H

Posted: Sat Oct 06, 2012 6:51 pm
by blue68f100
Glad no one was seriously hurt. He will definitely have to have his gun inspected by a good gunsmith to see if there is any other damage.

Sounds like an over charge to me. Or maybe a squid followed with a second round. But it should have barrel damage in this case. All of the 45acp I have seen fail normally split out at the case mouth. Normally on a 45acp since the pressure are low, the primer pockets will get loose before the case splits on good quality brass. Should be able to get over 20 reloads if not pushing max. But some of the newer brass is not of a very good quality and will only take 4-5 reloads before splitting the case mouth. One reason I do not like fast burn powders. Most will allow you to double and triple charge a case and still not over fill the case. And some powders are sensitive to set back, too.

Posted: Sun Oct 07, 2012 4:52 pm
by bigfatdave
Hakaman wrote:
I sure do like my solid aluminum grip panels.
Interesting thought BFD, do you think the aluminum panels would hold up in most cases?
H
I'm unable to picture an experiment I'd want to participate in to ctually test the theory.

Posted: Sun Oct 07, 2012 5:48 pm
by bgreenea3
I had a thread a while back on the same type of failure... I don't know about the alumagrips, as I had on the houge wrap around rubber type. but I imagine they would hold up to a case failure. I think the houges helped out in those respects as well.

http://guntalk-online.com/forum/viewtop ... ght=kaboom

Posted: Sun Oct 07, 2012 6:08 pm
by Hakaman
bgreenea3 wrote:I had a thread a while back on the same type of failure... I don't know about the alumagrips, as I had on the houge wrap around rubber type. but I imagine they would hold up to a case failure. I think the houges helped out in those respects as well.

http://guntalk-online.com/forum/viewtop ... ght=kaboom
That's exactly the way the failure looked, the brass looks identical. The floor plate flew about 30 ft, which signaled something was up, as I had my muffs on so I didn't hear it, just seen parts flying.
Question: Can a 1911 shoot slightly out of battery?
H

Posted: Sun Oct 07, 2012 9:13 pm
by bigfatdave
I'm sure B.E. would have more detail, but there is some tolerance in the disconnetor/slide relationship and the hammer/slide geometry.
So, yes, a little bit back from 100percent in battery is possible

Posted: Mon Oct 08, 2012 6:38 am
by Bullseye
It shouldn't fire out of battery (lock-up) if the disconnector's within specifications. Which is one reason why I'd do a quick function check and then look at the chamber. It was mentioned that these were reloads so an improperly loaded cartridge is highly suspect in this case. The barrel throat would be one of my next areas of inspection.

R,
Bullseye