Need a diagnosis

[Tom Servo]

These casings were taken from a lot fired by a customer at my range today. The loads are 115gr, standard pressure 9mm target loads. They are commercial reloads, from a reputable company.

Of 60 rounds fired, there were 11 failures. These are the worst four:









All were fired from a new Glock 19. Casings are a mix of Federal Commercial and Winchester. My first thought was that the wrong primers (magnum or small rifle) may have been used, but that wouldn't have caused the rupture in the 4th picture.

Oddly enough, I fired a few through a Sig P226 and encountered only one slightly bulged case. Recoil was consistent and normal, and the loads were reasonably accurate.

Could it be that the reloader is using weakened/stressed brass? He (like everybody) is doing double-time to keep up with demand. It could be some bad brass got through.

Also worth asking, would the extent of damage to the brass have anything to do with the chamber differences in the Glock?

[HiBC]

I do not claim to know.I can offer maybes.Who knows what the original weapon was they were fired in.Could be they had a little bulge in the unsupported area and were reformed by the sizing die.

Have you ever seen the stretch ring on a belted magnum case? It shows that when brass stretches,it gets thin real quick,and,all that working makes it brittle.

If you are real curious,break down some rounds.Pull the bullets,probe and look for stretch marks.Then section the case,through the flaw.

I do not have any experience with Glocks,so,no comment seems right.

[Mike Irwin]

1, 2, and 3 have all of the hallmarks of SERIOUS overpressure, especially judging by the condition of the primer in the third pic.

Too much powder, wrong kind of powder, load compressed by a too deeply seated bullet, whatever, it's bad news.

The fourth picture is a brass fatigue issue. I call it a burn through. It's where the case simply fails, either due to a micro crack, some other kind of weakness in the brass, an inclusion, whatever. It's not due to over pressure or anything like that. It's also not dangerous.

[res45]

Well this is my opinion,a Glock is a fine firearm but the unsupported chamber causes cases to bulge in the area pictured and weakens the brass. Sure it will resize out but the damage is already done to the case,the next time that reloaded case is used in the Glock with the unsupported chamber thats what you get.

Some people are pretty lucky some aren't. Thats why Glock states not to shoot reloads of course all mfg do that,and if you buy reloaded ammo or load your own from once fired cases fired in Glocks with unsupported chambers there's always a possibility of that happening. I always go through my range pickup brass and if is see the Glock bulge I trash it. It's one reason I don't own a Glock. If you don't want a KA BOOM stick with factory ammo or get an after market barrel. Problem solved.

Here's a pic from a Glock 40 that blew up with the same problem.

[SL1]

Would you please explain for us what you see in the third picture that causes you to say

...hallmarks of SERIOUS overpressure, especially judging by the condition of the primer in the third pic.

I see the marks that seem to indicate that the firing pin was dragged around in the primer while the case was moving during firing. But, the edges seem rounded and there doesn't appear to be any leakage around the primer. So, I would have attributed what I see to the ejection part of the cycle, with perhaps some disruption to that cycle caused by the case failure.

Any insights that further my education would be appreciated.

SL1

[res45]

The firing pin mark you see is actually the stand indention you see on ammo fired from a Glock. It's pretty easy to spot when picking up range brass

[Jector]

After reading res45's post I went looking and found the following site. Explains it all quite well.
A good explanation... Glock kB!

Essentially, as res45 said, those first three rounds were likely fired in a Glock before, maybe. I'm guessing that just by chance they ended up being chambered in the same orientation as when they were first fired so the previously weakened brass was again unsupported and, well you see the result.

Edit: Here's a snip from the article above over at The Gun Zone.com

The propellant AA#5 [See Annotation #1] has been identified in a disproportionate number of kB!s, not only in Glocks but USP40s with barrels which do provide full case support.

It would be interesting to know if the reloader is using AA#5. Can you find out?

[margiesex]

This happened to me some years ago - exactly the same issue. There was a combination of factors that eventually blew the grips off of my S&W Mod. 39 (I'm dating myself) and left me with a nice black powder hurtie down my palm.

Factor one: I interposed the numbers from the manual - ie instead of 4.6 - I loaded 6.4 - if you follow me.

Larger factor # 2: I retrieved all the brass from the clip and could follow the progression of the "bulge" from start to eventual blow out.

With help from my brother, upon tearing down the 39 I found that the excessive pressure of the overload was slowly but surely placing a small ring of lead in the bar. directly ahead of the chamber. In other words - the pressure caused the jacket to separate - lining the bar. with a bit of lead with each shot - eventually pushing the pressure even higher than that of the hot load alone - eventually there was not enough room for the lead core - causing massive pressure and POW - I learned a lesson!

Thank God no one was at the range, and no one got hurt. Needless to say, I am SUPER careful ever since.

God bless.

Margiesex

And remember: Hug your God and your guns - 'cause he's coming for them both, and soon!

[Mike Irwin]

"Would you please explain for us what you see in the third picture that causes you to say"

OK, and I fully admit that I may be wrong about this, but it looks to me that the primer is somewhat cratered and domed.

You, however, may well be correct in your assessment. We can't see the condition of the primers on the other two.

Back when I worked for the gunshop, we had a locally remanufactured brand of ammunition. The couple running the place seemed to be doing everything right, except that they would have some rounds with SERIOUS overcharges. We were never able to figure out exactly why, but their ammo was responsible for a number of pyrotechnical displays in a variety of firearms.

I still have several boxes of their ammo that I've been meaning to break down for years. I won't shoot it, that's for sure.

[Emerson]

I have seen this occur on a number of occasions.

Brass fired in Glocks get the little bulge are reloaded and fired in another Glock.............kabloooie

Unsupported chamber.

[Foxbat]

This has nothing to do with Glock, and everything with high pressure coupled with weak brass.

I have good collection of such brass, see the picture. All from one particular load - hot, but not too hot. As you can see, all blowouts happened to one particular type of brass - Winchester WB.

Furthermore, as you can see, it happened in a verity of guns, not just Glock - there were Beretta, Kahr, HK and Sig also involved.

ALL such events in that lot only happened to that brass, there were no other brands involved.

[Sarge]

There is simply insufficient data to make a determination.

[res45]

Which one would you feel safer shooting,after market replacement barrel on left or Glock factory barrel on right. The blown case in the first post was Federal the case in my post was RP both were reloads and fired from Glocks. the main reason it show up more is because there are more Glocks out there and many of the new mfg pistols have switched over to the Glock style barrels. It's just a poor design that was never meant to shoot reloaded ammo in.

[Tom Servo]

There is simply insufficient data to make a determination.

Don't worry: I am actually fishing for speculation. I just need to know what might be causing this, so I can pass the information along to the company.

Overpressure was my first guess, but oddly enough, they didn't feel any different when fired, and I'm usually pretty good about noticing that.

As far as the messy primer strikes, that's a hallmark of Glocks. The ammunition had problems with two guns, but the most dramatic failures were from the 19. The gun certainly wasn't the cause, but the brass certainly came out in worse shape from it.

[Foxbat]

"Which one would you feel safer shooting,after market replacement barrel on left or Glock factory barrel on right."

I have no issue shooting Glocks... I have 21 Glocks (or 22...), and regularly put thousands upon thousands of rounds down their barrels, I am not interested in Internet propaganda.

Here is one interesting bit for you... the 9mm ammo that had blowouts (see picture in my post), created different levels of problems in different pistols.

Kahr parts were thrown all over the floor, there was damage to the grip panel.

Sig suffered grip panel damage.

Beretta had to be disassembled - parts were jammed out of alignment.

HK P7 - grip panels damaged, gun jammed.

XD - blew up completely, had to be sent back to the factory - huge crack down the grip.

Glock 19 suffered NO DAMAGE AT ALL.

I have no aftermarket barrels in any of my Glocks.

[Tom Servo]

I have 21 Glocks (or 22...)

Wow...I thought my dedication to S&W K-Frames was unhealthy

Here is one interesting bit for you... the 9mm ammo that had blowouts (see picture in my post), created different levels of problems in different pistols.

Interesting. I've seen the exact same behavior with Berettas (usually, the trigger bar is pushing the grip panel outward) and Sigs with overpressure ammo, and I've seen it lock up a P7, as you mentioned.

Very disappointed in the XD, though.

[Mike Irwin]

"Overpressure was my first guess, but oddly enough, they didn't feel any different when fired, and I'm usually pretty good about noticing that."

Hum...

Most times you WILL notice a difference in feel in an overpressure round. You'll also hear or see it.

I double charged a .45 ACP some years ago and fired it through my Springfield MilSpec.

9.8 grains of WW 231 makes itself very noticable.

[Farmland]

I would suspect over pressure the case looks just like the one I posted in a thread during the summer. I had made a mistake and gave it too much powder. However the case with the budge looks 100% to my case except the head stamp had blown off.

The case with just the crack looks like a few that I get every now and then from brass that has been reloaded past its prime.

NOTE: my case failure was in a Beretta 96. It broke the extractor and pushed the trig bar out into the side of the grip.

[flyguy958]

I'm a novice by most standards, all but #4 looks like too much pressure to me.


"Here is one interesting bit for you... the 9mm ammo that had blowouts (see picture in my post), created different levels of problems in different pistols."

"I have good collection of such brass, see the picture. All from one particular load - hot, but not too hot. As you can see, all blowouts happened to one particular type of brass - Winchester WB."

Foxbat, at what point do you back up and punt on this load? Four guns blown up? Do you still shoot this load?

[snuffy]

Glocks aren't the only ones that will blow a case when presented with an overcharge. For example;



That was fired with had to be a double charge that was supposed to be the starting charge of a bulk powder I have. Pistol is a SA 1911 45 acp. Gun was undamaged, it has rubber grips, otherwise I'm thinking wood grips would have cracked.

As for the reason, hand throwing charges in a load work-up. If I had been using the disc measure in auto turret rotation on the lee classic turret, it wouldn't have happened.

[Mike Irwin]

"I'm a novice by most standards, all but #4 looks like too much pressure to me."

No, most likely not.

I've had similar case failures with light .38 wadcutter loads. It's a case failure caused by a flaw of some type.

[Foxbat]

"Foxbat, at what point do you back up and punt on this load? Four guns blown up? Do you still shoot this load? "

I have to admit, I was curious about its behavior in different guns, mainly due to consistent stream of glockophobia. Turned out Glock was perhaps the most resistant to this type of a failure.

After the early incidents I simply started shooting wearing gloves, that made all the difference - without them my right hand had a persistent sore on top of the palm.

Having done my tets I simply sorted the whole batch - there were several hundred rounds still left. I segregated the Winchester ones, and pulled the bullets. The rest of the batch fired without any issues.

[Foxbat]

"Wow...I thought my dedication to S&W K-Frames was unhealthy "

Nothing's unhealthy on forum like this one!

Here is one of my Glock racks, I have three.

[Brian Pfleuger]

Originally Posted by res45

Which one would you feel safer shooting,after market replacement barrel on left or Glock factory barrel on right. The blown case in the first post was Federal the case in my post was RP both were reloads and fired from Glocks. the main reason it show up more is because there are more Glocks out there and many of the new mfg pistols have switched over to the Glock style barrels. It's just a poor design that was never meant to shoot reloaded ammo in.

It should be noted that not all calibers in the Glock line up show such an extreme unsupported area. My Glock 33 (357sig) has better chamber support than the aftermarket barrel in those pictures:



While my Lone Wolf barrel actually has WORSE support than stock:



On another note, I'm a complete novice but those primers look very normal to me. I've been using Federal primers in my reloads and they almost universally flatten and mushroom slightly regardless of load from 7.1gr all the way through 8.1gr Power Pistol with Hornady 124gr XTPs.

[SL1]

Foxbat,

Is it possible that the Winchester cases were previously fired in a glock, perhaps even with excessive charges, before they were reloaded and fired again to create the blown-cases? Or, did they blow when they were fired as WW Whitebox loads?

SL1