I'm gonna try this at the skeet range.
A picture is worth a thousand words.
PULL!
Posted on 02/28/2007 11:52:31 AM PST by archy
Catastrophic Failure of Semiautomatic Handguns
The following bulletin was received from the New Jersey State Police - Officer Safety Division
Date: February 23, 2007
Continuous reloading an chambering of the same round may cause catastrophic failure in semiautomatic handguns.
The Security Force at the Los Alamos National Laboratory in Los Alamos, New Mexico, recently reported on the catastrophic failure of a semiautomatic handgun when it was fired. The internal explosion caused the frame to break while the slide and barrel separated from the weapon and traveled down range. No one was injured in the incident. An investigation revealed that security personnel were repeatedly charging the same round of ammunition into the chamber.
Technical personnel at Glock Inc. advise that repeated chambering of the same round may cause the bullet to move deeper in the casing, further compacting the prpellent. When a normal cartride is fired, the firing pin his the primer, igniting the propellant. When the propellant burns, the gas pressure drives the bullet out of the case and down the barrel. However, if the propellant has been compact, the pressure may increase beyond the gun's specifications, causing the weapon to break apart. Sigarms Inc's peronnel confirm that reloading the same round five or six times will cause the problems, noting that reloading the same round even once will void their warranty. Both manufacturers stress that the problem is not with the gun, but with chambering the same round repeatedly.
The NJ Regional Operations Intelligence Center urges all law enforement officers not to chamber the same round when loading their weapons.
***For example, when you clean your weapon, most of us drop the magazine and then pull the slide back thereby ejecting the round in the barrel. After cleaning the weapon many of us will return the "same" round to the barrel that we initially extracted. Each time the slide slams forward on that same round it seats it deeper into the cartridge. Apparently, by seating the round deeper into the cartridge, it creates greater pressure when the round is intentionally detonated by a firing pin strike and is causing weaopn's to explode.
-xxx-
Great in theory. But cops have to unload every time they deliver prisoners to a jail, often when they attend court as witnesses in jurisdictions where only the court bailiffs/judge's bodyguards are allowed to be armed.
Likewise military *green zone* restrictions on carry of a chambered round require hitting the old *clearing barrel* every time you enter or exit.
And frequent maintenance and inspection, daily at least, requires the same. Neither is this a problem limited to crap ammo, though the .40 S&W round commercial loadings seems to be worse about it than most- and are also very sensitive to the overall length of the loaded round during the feeding cycle. There's a real problem here, maybe a couple. There are likely more than one answers to them, too, rather than any one simple one.
If the charge is already in contact with the base of the bullet, it might not take much setback to compress the charge ... if in any doubt at all, measure OAL of your carry rounds ... compare against a few fresh out of the box. It can't take more than a few minutes.
This is finally an explaination of the "kaboom" phenomenon, over-attributed to Glocks (note that Sigarms issued a "don't do that", implying the same issue).
This is common behavior, "clearing" it for assorted safety reasons then loading the same ammo later (entering & leaving a cold range, storage, air travel check-in, interstate ground travel, cleaning, etc.). Often will use one kind of ammo (possibly quite expensive) for carry, and another for practice (possibly quite cheap), and load the same ammo in the same mag repeatedly - as the carry load is not often used, a few rounds may get chambered repeatedly.
When chambering a round, the mechanics of chambering can compress the round. Apparently it doesn't take much compression to cause a significant increase in pressure. This is magnified by serious defensive needs leading to use of extra-powerful so-called +P or +P+ rounds, which are straining the limits of safety already.
why would you regularly a glock with a round chambered?
You're missing a key word there. Presumably it's "carry".
It's perfectly normal to regularly carry a Glock with a round chambered: pull trigger, go bang - just what you expect. If you need that bang, you don't want to waste time fumbling around with chambering a round. Also, it gives you an extra round (X rounds in the mag, plus 1 in the chamber).
Maybe. But less so if it's not the top round in the magazine having been covered by another as magazines are switched and chambered rounds replaced in the magazine in the gun belt pouch rather than always removing the mag from the gun and topping it back up.
I've done it myself, with Browning GPs and M1911s, and others.
Color me skeptical.
You are trying to tell me that a round with a muzzle velocity of 1200-2000 fps simply blows a perfectly good gun apart because the round is pushed a miniscule distance further into the casing?
What is stopping the round from leaving the casing?
Is the burn rate of the powder SO FAST that it is overpressuring the ammunition case AND the the metal of the handgun, simply because it is pressed 1/1000th of an inch further into the case? If so, I'm assuming that handguns just blow up all the time with people who load their own rounds.
This doesn't sound right.
Methinks it has more to do with the steep feed ramp affecting seating.
May not take much change in seating. +P[+] ammo (presumably used for serious Los Alamos type security) is already stuffed to the gills, so slightly deeper seating may have a significant effect.
I was under the impression that some of the KB problem, particularly in Glock's in .40 S&W was shooting lead reloads as opposed to jacketed.
Well it's not! I have been loading the same Glacier(sp) round in my 1911 every Thursday for over two years to get ready for work. It won't happen this week.
Yes, that's what we're trying to tell you.
Department regulations would be one excellent reason. Another is having attended the funeral of a pal who had carried his handgun with the chamber empty for *safety* reasons.
Yep, almost certainly some have been. Most, however, were not.
If this is the case, and the the malf occured on the 1st round with the bullet dislodged from the stretched out casemouth, then the pressures would have been lower and no catasrophic failure would have occured.
I accept that I could be wrong on this, but it just does not make sense as put forth.
Funny, then, that these problems and *phase three failures to feed* have not been as frequently observed in handguns chambered for the .357 SIG, which uses the .40 S&W cartridge case as its parent dimensions, and usually utilizes the same feed ramp and magazine as the .40 guns, with just a change of barrel [and sometimes, recoil spring] to effect the conversion.
Well, why isn't ammunition manufactured so that the case has a small lip that physically will not allow the round to be inserted any further into the casing? This is a no-brainer.
If you drop a round of ammo, pick it up, dust it off and inspect it to insure no nicks or gouges, it could STILL blow up because the round was pressed deeper into the casing?
It would seem that the ammo manufacturers would be wide open to a costly lawsuit.
I'm gonna try this at the skeet range.
A picture is worth a thousand words.
PULL!
Back in my NRA trainer days, our group tried to discourage the use of Glocks on the range. We referred to them as 'Glops'. We had more trouble with Glocks than any other semi-auto pistol.
I'd also need a kevlar towel hanging from my belt. :)
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