What are the definitive specs for in out of battery for a glock, regarding oob firing

[briandg]

I couldn't really find a perfect answer by searching so I'm starting a new thread about the specifics.

had a case blowout I don't have all the information to share just yet, but here are some of the facts. Pin strike was dead center and nothing offhand seemed unusual about the primer. Putting the case back in chamber, it's really hard to tell what happened. The thing will go completely into battery, but it seemed to have slid out a bit between igniting and blow out. The tear started exactly at the junction of the taper and flat edge. The case didn't eject. I didn't locate a case I could identify as the previous round. The barrel was spotless.

Nothing at all seemed unusual, some sound, and other than the solid "WHOMP!" Nothing felt unusual.I have smoke stains all over every source of possible leakage on my hands.

So the point is that this thing almost certainly was in battery when it blew out at the web of the case. I know absolutely that it wasn't the round at fault. Not a chance that it was overcharged. It was 115 grain factory lead bullet. Mid range charge. In spec all the way. I have run thousands of these rounds through another pistol, and hundreds through this glock.

So I keep coming back to the same circle. No obvious failures in equipment or ammo, was it the brass? Plain federal, nothing unusual, only a few loads, I guess.

Am I missing something? Is this just a case of the brass owing out from metal failure or other cause? Is this what a person would expect to happen with a very small overcharge of aa9, a moderately fast powder?

This is my first failure of ammo like this.

The last question is whether or not to have it checked by a gunsmith now

 

[briandg]

Going over it at 50 x it seems certain that it was bad brass.

 

[James K]

I guess I am behind the times, but I was unaware of any factory 9mm using lead bullets. Is it possible that the ammo is reloaded?

I am sure you are aware that Glock has consistently warned against use of lead bullet ammo in their pistols. I am not sure I fully understand why or what happens but there have been so many reports of problems with lead bullets that they cannot be ignored.

One thing is sure; the gun did not fire out of battery. Had it done so, you would not be asking about having the pistol checked out; you would have a completely wrecked pistol. It sounds like a brass failure which allowed gas to escape but not fast enough or in enough quantity to do severe damage.

I am sure others will offer advice, but mine is to stop using that ammunition; contact the ammo maker and arrange to have it returned for analysis. If you don't have original boxes (another product of the famous Plastic Bag Ammunition Company), simply stop using the ammo or use it in a gun where the case will be better supported, like a Ruger convertible revolver.

Jim

 

[g.willikers]

Don't mean to add to the confusion, but..
Why couldn't it have been an overloaded case?
Factory ammo isn't immune to mistakes.

Not a chance that it was overcharged. It was 115 grain factory lead bullet. Mid range charge. In spec all the way.

Or was it a reload?
And how did you determine if the round was in spec?

 

[briandg]

It's all in the writing and reading. It wasn't a factory ammo, it was a factory manufactured Len that I handloads.The load was as nine, I've used several pounds of it, and these are the last few of the thousand bullets. I guess that the first 750 00or so went through another pistol.they've worked alright in the glock after I tweaked the crimp.

I've been literally spooked half death using lead, and don't intend to continue. Coated, may b probably plated, no more naked lead. I've heard about the kabooms, but so much of it seems to be extreme use, not some tool like me who goes through several hundred a year for each of his guns, and cleans every time. My chuckle headed older brother went through thousand, an he was one of those guys who removes lead build-up with a box of fmj. I've maintained real caution. They don't like reloads, either.


Seriously, I don't think it can be the load, and the punch was dead center, so out of battery seems unlikely. Matching the case to chamber it seems proper. As far as I can see, this tear started at a point that the chamber was fully supported, to the left. There is a square tear that peeled counterclockwise. There is a mark that appears to have happened when fully in the chamber, an it tore a bit higher. One of my greatest questions is that this brass must have been extraordinarily brittle. The tear is granular all the war, not even a bit cleanly sheared. It's even coarser than 20 grit s a nd paper.

I'm not trying to convince myself that it wasn't my fault, I just can't see and evidence that the load or gun was at fault.

I scrubbed the pistol spotless. The only damage is the magazine, the notch for the lock is called, but it held. I found a few flecks of lead. There seemed to be a very narrow ring about half way, it was bare visible, and didn't obscure the rifling. It couldn't be felt on the brush, but I did feel a bit of drag on the patch.

I'm going over that case again tomorrow. You're limited as to what you can see with magnifying glass as and a jeweler loupe.

Seriously, does this really sound like a fault in either the ammo or the gun?

 

[briandg]

(Wikimedia Commons drawing by Morgan Phoenix, under Creative Commons license, unaltered.)


Hard to explain, but it tore right at the front of the flat extractor groove is cut, ripping off that angled face starting at around 7 and reaching almost to four. I'm still not sure why the thing didn't eject.

 

[Mobuck]

Blow out at the unsupported area of the chamber happens occasionally. I've seen it happen with a Star that had been improperly "throated" and a factory stock S&W6906. Both instances appeared to be bad brass from the same lot of commercial reloads.

 

[45_auto]

I know absolutely that it wasn't the round at fault. Not a chance that it was overcharged.

How do you determine that on a fired round?

It wasn't a factory ammo, it was a factory manufactured Len that I handloads.

Putting the case back in chamber, it's really hard to tell what happened. The thing will go completely into battery,

I've never seen an out-of-battery failure where the gun would go back into battery with the expanded case in the chamber. The brass expanding into the ramp before it blows takes the out-of-battery shape and will hold the slide out of battery when re-inserted into the gun. If the brass fits the chamber, it's a pretty good sign that it was fully chambered when the gas vented.

Hard to explain, but it tore right at the front of the flat extractor groove is cut, ripping off that angled face starting at around 7 and reaching almost to four.

It's not a coincidence that what you describe is the exact same shape as the feed ramp cut into the bottom of the chamber where the brass is unsupported. The overpressure caused the brass to expand to try to fit the feed ramp at the bottom of the chamber. Brass isn't ductile enough to do that, so when the stress exceeded the ultimate strength of the brass it tore.

I'm still not sure why the thing didn't eject.

It didn't eject because the overpressure that blew the case out had the brass expanded into the chamber till AFTER the extractor jumped the extractor groove. The slide (with extractor) and barrel started moving rearwards at the exact same time the bullet started moving forwards (recoil operated). The extra pressure caused greater acceleration on the bullet therefore greater acceleration of the slide/barrel. When the barrel unlocked from the slide the spring-loaded extractor jumped the groove and moved further back than the end of the cartridge before the pressure dropped enough to permit the brass to contract.

Seriously, does this really sound like a fault in either the ammo or the gun?

99.99999% chance that it was the fault of the ammo, as in an overcharged round.

Is this what a person would expect to happen with a very small overcharge of aa9, a moderately fast powder?

Yep.

I've had the exact same thing happen with a Glock 20 (10mm) with Longshot. Kept bumping the load up, got some significant smileys (creases due to expanding into the loading ramp) which I didn't pay attention to until afterwards on a few pieces of brass even though it was still under the reloading manual max, then BOOM - next increment blew the side out of the case at the feed ramp, stripped the mag notch and blew the mag out of the gun, and cracked the trigger. I'll try to post some pics of the case when I get home tonight.

The last question is whether or not to have it checked by a gunsmith now

I wouldn't worry about it. Take it all the way apart, inspect for damaged trigger pieces, and consider it a warning to be very careful when you're reloading.

 

[briandg]

Thing is, that nobody alive has more safety processes than I do .really. weigh twice per block. Count each round as I charge the block. Visual check of the block, then usually I push the bullets in by hand before I start seating. Anything seems wrong, I dump the whole block, make sure that they are absolutely clean and start over. I use powder that has low density, so overloading is more evident, and I keep loads lower. There are so many more. There is, in any case, a chance that I made a mistake, or there was another error, but something like this blowout with a slight overcharge seems really unusual. There were never any other signs of pressure.

I have to agree with everything you said, even to the possibility of an overcharge, and I still feel spooky about using lead, even though there is no evidence remaining of fouling. That ragged, ripped out case just doesn't look like anything else I have ever seen.

 

[briandg]

What does it sound like with that barely visible wrong of fouling about half way up the barrel? Did that form when the case blew and the fire went out, so to speak? I found powder residue in the case, some on the tear out.

 

[briandg]

Now I have dug really deeply into internet files and coming a possible cause. Over crimp. I am at least reasonably convinced, but I still question the case metal. Looks like it was my fault. I should have done better research.

What is the best answer about plated or poly coated bullets? Steel case factory? Obvious answer is to stop shooting it, and go back to my revolvers, and only use factory when I can afford it, and only for practice, as it costs so much for top line ammo, and just get rid of all of my relaxing stuff to stay within glock rules?

I genuinely appreciate all of the help thinking this through. I hope that it's helpful to other people. It also seems that trading to an after market barrel with a better ramp and conventional rifling.

I'm not concerned about a true gun disintegration, just general failures.

Lord I hate this kindle and auto thext..

 

[45_auto]

I know absolutely that it wasn't the round at fault.

....

Thing is, that nobody alive has more safety processes than I do .really.

I'd be willing to put my reloading safety processes up against yours.

My daytime job is in a very unforgiving industry (manned space flight) with extensive engineering safety and quality checks and signoffs on EVERY item and process that are unbelievable and incomprehensible to most people. And things still slip by.

The fact that you believe that you "know" something ABSOLUTELY that can't be proved and believe that no one has more safety processes than you do seem to me to be signs of overconfidence that are just waiting to bite you, and probably did.

Visual check of the block, then usually I push the bullets in by hand before I start seating.

Anytime one of your processes uses the word "USUALLY" in it's description, it's a red flag that you aren't doing everything the same way every time.

 

[Dixie Gunsmithing]

My guess is the same as Jims. I'd say it was a brass failure. It was most certainly not the pistol coming unlocked. Brass cartridge failures in reloads can be caused by several things, including brass that ruptures from being stressed over reloading too many times, or an incorrect charge. Plus, as Jim says, there's something up with Glock and plain lead ball ammo, and what that is, I've never heard anyone clearly state, though one would think that it would not make any difference. However, it would not cause it to unlock, as if it ever did that, then you would most likely have a ruined gun, and a possible injury. Also, many guns have the case unsupported at the feed ramp, by a small amount. The brass is thick there, (the depth of the primer pocket), which remains so on into the chamber, where it is supported. However, the brass can still rupture, if it has been continually over stressed in that area by multiple reloadings, especially around the extractor groove. I'd say that it has a lot to do with the design of the guns chamber, in how many times you can safely reload the same brass, and the manufacturing and quality of the brass that you're using.

From the pic above, you'll notice that the distance from the inner cavity of the cartridge, to the extractor groove, is not as thick as the thickness longitudinal to the primer pocket. It is probably only 1/2 as thick, providing that your cartridge is manufactured the same way. There is a possibility for it to be thinner there, according to the manufacturer.

I'd bet that with new recommended ammo, you'll never have another problem with it.

 

[briandg]

Alright 45 auto, that wasn't a really good thing to say. The "usually came from the frequent times when slipping the bullets into expanded brass just won't work. I still believe that my procedures are as good as I can do, but r
You are right, the fact that it failed eventually points to me in some way.

Dixie, I believe that I have finally got it figured out. Your point of it tearing out at the web, leaving a jagged, sharp surface, instead of blowing out at ten center where the brass is weakest ,tearing away the web of the base, was my most confusing part. I have now come up with an answer, I hope. I have spent some time with an inertial puller. I had a line board placed on a solid bench,and pounded on it until my shoulder hurts. Out of five attempts only one pulled. It's going to the waste facility.

So I screwed up, and built over pressure rounds that resulted in an eventual case failure, for reasons I believe to be bad metal in a once fired federal case. I can be pretty certain that it was once fired brass because it was purchased as once fired in a bucket, and the bullets were from the very first batch I ever bought. As I retrieved these I was dumping them straight into recycling anyway, and the only reason I was shooting them at all was to just get them off of the shelf. Once again, thanks for talking me through this and I hope it helps some I
Others out.

Again the whole batch of fifty or so remaining loads are going to the place of execution.

 

[Sevens]

Why do we have seasoned handloaders convinced that they need a "crimp" in handloaded ammo designed for a semi-auto that headspaces on the case mouth?

I wish we had better terms for what we need and what we do. On 9mm, we need to remove the case mouth flare that we imparted earlier. The loading die companies may love to call the finishing step a "crimp" but in 9mm, you shouldn't be trying to pinch or grip that bullet in place. Case mouth tension and proper sizing handles that, NOT your "crimp."

 

[45_auto]

It was 115 grain factory lead bullet. Mid range charge. In spec all the way. I have run thousands of these rounds through another pistol, and hundreds through this glock.

...

Is this what a person would expect to happen with a very small overcharge of aa9, a moderately fast powder?

Where are you getting your load data? My Lyman, Speer, and Hornady manuals as well as the Accurate online data show nothing slower than AA#7 in a 9mm. You have to move into the 357 SIG pressure ranges before they start showing data for AA#9 on cartridges with such small volumes. If you're using data from some internet yahoo without access to pressure testing equipment, or experimenting on your own, don't be surprised when things go "BOOM", even if you have gotten away with it for awhile. Safety factors built into modern data are there to protect people from statistical outliers like weak brass, bad crimps, etc. Nothing wrong with pushing the limits, just don't be surprised when they push back sometimes.

Latest Accurate Load Data Guide is here. Take a look a page 5 and look at the cartridges that a slow pistol powder like AA#9 is recommended for. Note how most of them have "Magnum" in their name or are high pressure large volume cartridges.

http://www.accuratepowder.com/wp-content/uploads/2010/09/WesternLoadGuide1-2016_Web.pdf

Nothing wrong with going off doing your own thing despite the manufacturer's recommendations. Elmer Keith had a great time doing it and he only blew up a couple of guns. Just be aware that when you're working with pressures in the 30,000 PSI to 40,000 PSI range (think of it like a half dozen Chevy Suburbans sitting on every square inch) it doesn't take very much to cause all kinds of interesting things to happen, like blowing through a thin piece of brass.

Now I have dug really deeply into internet files and coming a possible cause. Over crimp.

Do you have access to a micrometer or at least a caliper to measure the mouth of the case after you crimp it? As Sevens pointed out, the 9mm headspaces on the case mouth.

SAAMI 9mm case dims are here:

http://www.saami.org/pubresources/cc_drawings/Pistol/9mm Luger - 9mm Luger +P.pdf

 

[Unclenick]

Everyone posting images

Briandg,

I have corrected your post of the Wikimedia Commons image to comply with their attribution requirements under their license for you to make copies. FYI, this requires the author's name and a link to the license be posted with the image, along with whether or not you altered the image in any way. Please do the same in the future.

Government drawings released to the public may generally be posted without comment. Please see the board rules on posting copyrighted materials.

Bad or defective brass seems the most likely cause if you owned the brass from when it was new. If, however, it is a range foundling, you have no way to know what's been done to it before. Somebody may have fired it with +P loads multiple times, weakening it.

If the brass was made overseas (and some domestic brands outsource overseas, too) by the process of drawing a cup from a disk rather than by pressure forming a slug, you sometimes see folds in the inside head area where it wasn't pressure welded properly during forming. This can leave a weak place that separates as you described.

Since the barrel has no visible leading, I don't think that was the issue here. Leading in a Glock does damage by raising pressure, and what you describe doesn't fit a high pressure discharge well. I had a double-charge twenty-some years ago in a 1911, and it locked the gun with the slide back only slightly and had to be hammered open. It cracked the grip panels and smashed and bent the top two rounds of those remaining in the magazine. Hot gases and brass fragments blew back in my face (thank God for glasses). The gun held together, but the barrel had a 0.003" bulge just ahead of the chamber and had to be replaced. If that had happened to you, you'd know it.

The mechanism of the Glock leading was described by someone who had a blow-up after firing many lead rounds successfully and despite checking for leading multiple times during the firing session. Apparently a lead bullet will strip in the polygonal rifling more easily than in conventional rifling. But where stripped lead builds up the turning edge of conventional lands, it fills the corners of the polygon in a polygonal barrel. As those corners fill the amount of grip on the next bullet is reduced, so that one strips, too, and so does the one after that and etcetera, until you have a smooth lead-lined bore that is narrower than a bullet. That can all happen in the space of just a half dozen rounds once the first one has stripped, raising pressure considerably. So unless you check for leading after every two or three shots, it is better to get one of the conventionally rifled aftermarket barrels for shooting lead through the Glock.

 

[RKG]

Bearing in mind that all long-distance, sight-unseen diagnoses are speculative, herewith my speculation:

1) I actually don't think you had an out-of-battery firing, which I believe is properly defined as the round of ammunition igniting before the action goes into full lock. Whole bunch of reasons, but generally OOBs (apart from cook-offs) are related to inertial firing pins, and a striker-fired pistol such as a Glock has the firing pin mechanically locked in the retracted position until the sear releases.

2) Rather, I'm with those who vote for a failure of the brass while under some level of residual chamber pressure. In the main, this results from a combination of excess charge and some degree of unsupported case. You ask us to assume no overcharge, and you report having fired lots of loads of purportedly the same pressure from the same pistol using the same brass, which implies that lack of support is not endemic. So what could have happened?

3) What is left, and what I suspect happened, is premature unlocking.

4) In any self-loading pistol, the mechanism that wants to cycle the action (in this case, recoil operated) tends to want to begin cycling immediately, and at a point where residual chamber pressure is still too high. So there much be some way of delaying that function long enough for the bullet to exit the bore and chamber pressure to vent to the atmosphere. In a blowback pistol, we rely on inertia of the comparatively massive slide and the comparatively heavy recoil spring to delay rearward motion of the slide. In a locked breech pistol, we rely on the time it takes for the locked slide-and-barrel combination to move far enough aft to achieve unlocking.

5) If, for some reason, the amount of delay (in time) achieved is insufficient produce the reduction (in pressure) required, the case will become unsupported by partial extraction at pressure.

6) Which leads to your choice of propellant. As others have observed, A9 is a very slow burner, and so far as I'm aware, not recommended by any source for 9mm rounds. Slow burning means that, at the instant before the slug exits the muzzle, residual combustion chamber pressure is higher that it would be, for instance, using Unique. Couple this with the use of cast lead slugs, which tend to have a lower coefficient of bore friction than jacketed slugs, which in turn means that all other things being equal (i.e., propellant charge and burn rate) they will exit the bore sooner.

7) So, I think you had a premature unlocking and premature extraction, versus an OOB, that was caused by a combination of lead slugs, the slow A9 propellant, and the laws of chance. One telltale would be unusual marks on the rim, as the extractor labored to extract the case while still under pressure.

8) I'm not a Glock guy. Nor do I shoot lead slugs from 9mm pistols (though I do shoot a lot of 9mm). But if I were shooting lead slugs from a 9mm pistol, I'd load with Bullseye and Unique, and I believe that with these propellants, the probability of a premature extraction is just about nil.

As I said at the outset, there is a bit of speculation here.

 

[briandg]

Sevens, whatever we call it, I have always use a taper crimp in the same manner. Oalll specs left the brass just barely de flared, and it worked in my Browning, which I won longer have. This didn't work in the clock, for one or another reason, and ill address that if I start loading for this one. Lyman expand dies as I bought them double for 38 acp and this obviously must be addressed.

Auto, let me say something up front. I had a brain abscess two years ago resulting in three minor operations and a series of earlier issues that left me with various problems, one of which is communication..logic and technology weren't affected, only left brain.

What happened was that I used number two, but the number nine came out instead. When I was making up loads for heavy use, I chose he six, rather than five, and that worked well. It reached full velocity over a chronograph, and I dropped it back .2 grains. Should have been safe and effective.

I do use calipers routinely, as well as high magnification examination. You'd be surprised at what brass looks like at extreme magnification. I did numerous times trying to figure out why it didn't feed right in the first place.

Thank you, Nick, it's hard to keep up with procedure, and this is one of the reasons that I exercise so much caution. I completely abandoned shooting and reloading for many years because of the burnt out issues, but finally recovery to this point.,

It was once fired federal purchased from a company said to have bee reliable. It all passed a casual inspection. I do agree that it could have been worn out, but that cartridge looked fine, even after the blowout. No breech marks. It's doubtful that it was fired numerous times, by my observation. Dry brushing with a stainless brush came up with no obvious lead on sight, but upon a very serious scrubbing at home, a few sliver came out, but I feel certain that this minor lead fouling wasn't an issue. Your explanation is exactly as I have heard it before. I clean every pistol I use after every session, steel brush and rag, and would rather chance wearing out a barrel than blowing it out.

Come on, guys, don't mistake me for stupid, I've listened carefully to everything I've ever learned and heard, and follow it. This thing, no matter how I looked at it seemed to be a riddle, and you guys and one sentence in another source seem to have answered it. More to follow.

 

[briandg]

Here is the answer as it best explains all of the answers. I wasn't thinking, and accidentally tossed the fired brass into the recycle bin without completely examining them.. a casual look over showed no errors in the field.

Now here is what I thing happened.

I tried to pull down the rounds last night with an inertial puller. To my surprise, I couldn't. I put a pine 2+4 on my solid bench, and hammered until my hands hurt, and only one bullet pulled. Yes, a nine 115 has very light momentum, but the beating I gave them should have worked. .223 rounds and 125 .38 rounds never caused this.

I'm thinking that blowing the bullet out of a tight grip and then forcing it into the barrel caused very elevated chamber pressure
. It went unnoticed because it only spiked at the chamber, I couldn't observe any further differences.

As we've discussed, I believe that the brass was not good. It was probably fine for normal rounds, but a number of rounds. Must have had high chamber pressure that badly overstressed any weaknesses.

I have already dumped this ammo into a disposable bud, but I think that ill pull it and dump it in bleach to corrode it to a point that nobody but an absolute bonehead would grab it at the facility and try to use it. .

I'm on my way to the range pretty soon and intend to find as much of my own brass as possible.

This part is bound to get me slapped, but here it goes. I had laid up a target, returned to my shooting point, and fired a round. I forgot to put on my ears and eyes. Three rounds later, ka pop.

NEVER FORGET PROTECTION. that's for my own enefit. I have literally a half dozen pair of glasses on my bench. I have a half dozen ears. I have a checklist I follow for things like this, but one day found myself at my destination without my pistol.

I know that this sounds terrible, but it's white quit for so many years. Eventually, you adapt, and take e v very precaution. People take these things for granted. My situation is like attention deficit, and no level of precaution is being too careful.

Can any of you guys imagine staring at your range bag for five minutes minutes, trying to determine whether you have everything, then going over the checklist, and finding out later that you left home the ammo for the second pistol? Oh, yes, the list said "ammo" nd there are .38 rounds but no rifle ammo, nor a spotting scope.

Ill post later is I find any thing on the brass, then I guess I'm finished, problem almost certainly solved.