OUCH, that hurts !

[clemmac]

CCI Blazer aluminum cased ammunition, .40 S&W caliber. Generation 4 Glock M-22 pistol. Not a particularly dirty pistol. Moderate rate of fire, pressed the trigger and got a hard slap in my shooting hand. I glanced down at the pistol and my hand, no blood, my hand and trigger finger suddenly had black sooty stuff that wasn't there before. I also felt some small bits of material hit my face. The magazine was blown part way out of its well, and the slide and barrel were maybe 1/8" out of battery. The blown case did not eject and I could see it sticking out the back of the firing chamber.

The magazine's catch notch is partly sheared off, kinda rounded now, the magazine catch itself looks like new. The magazine was still usable except for being tight in the magazine well, it must have expanded when the puff of hot gas pushed down that way. It is one of my practice magazines, so no huge loss if it fails sometime later.

The fired case was damaged as the pictures show, I don't know what happened to the primer, the area where the double Berdan flash holes normally are is completely missing too.

Did the gun fire while it was still a little bit out of battery ? Did I just have a blow-out of a bad case or a cartridge that had an over charge of powder ? Was God giving me a warning (humor) ?

I'm a Glock armorer, subsequent to this happening, I did a complete disassembly, cleaning and inspection of the pistol and found no obvious problems except to the magazine I was using, a little squeeze in the vise fixed it up so it'll drop free again.

For those who don't know what CCI Blazer aluminum cased ammunition is: it's generally less expensive, but very reliable and safe training type ammunition. The aluminum cases are made with the Berdan priming system to discourage any reloading of the fired cases. Berdan primers are specialty items, not widely available, and spent primer removal is difficult without specialty tools.

[JoeH]

I'd blame the Glock.

[clemmac]

I'd blame the Glock.

Oh poop, I really didn't want to start a 1911 vs Glock war .................. honest This was for information and interest only.

Clem

[usnret]

Looks like it is time to get some free ammo from the good folks who make Blazer.(CCI/ATK)

[timwarner]

I've blown out a few cases with very high pressure reloads. glocks handle them well.

It's pretty much a hand slap feeling and sometimes the mag drops.

Kinda concerning if it happens with factory ammo though.

edit: After I look at that pic a bit, that looks really messed up. Where does that blow out portion fit in the barrel?

[minnesotatv]

looks like a classic Glock kaboom.

unsupported area of the case lets go.

Glad to hear you weren't seriously hurt.

more info here: http://www.thegunzone.com/glock/glock-kb-faq.html

[clemmac]

I've blown out a few cases with very high pressure reloads. glocks handle them well.

It's pretty much a hand slap feeling and sometimes the mag drops.

Kinda concerning if it happens with factory ammo though.

edit: After I look at that pic a bit, that looks really messed up. Where does that blow out portion fit in the barrel?

I think it blew out the bottom of the case.

I do NOT reload 40 S&W anymore, quit that a few years ago.

[timwarner]

the blowout is at the front instead of the back. Normally a blowout will be towards the case head. That looks like a reverse one.

[1911fan]

Classic Glock KB. Gun fired slightly out of battery case wall lets go and 38,000 psi has to go somewhere.

[macphisto]

the blowout is at the front instead of the back. Normally a blowout will be towards the case head. That looks like a reverse one.

Huh? It blew out right where you would expect it to, by the feed ramp where the cartridge is unsupported in a Glock barrel.

This made me laugh until my stomach hurt:

I've blown out a few cases with very high pressure reloads. glocks handle them well.

[timwarner]

the blowout is at the front instead of the back. Normally a blowout will be towards the case head. That looks like a reverse one.

Huh? It blew out right where you would expect it to, by the feed ramp where the cartridge is unsupported in a Glock barrel.

This made me laugh until my stomach hurt:

I've blown out a few cases with very high pressure reloads. glocks handle them well.

the couple KB's I've had blow out from the front, not the back.
The case web is thicker towards the back, so generally it gives up in the front and peels back.

Not saying it's a glock thing, i was running estimated 55k psi loads.

[Grandpa Rex]

It appears the gun gods were smiling on you...good to hear you and your gun are largely undamaged.

The other remote possibility is bi metal corrosion weakened the case. That would only happen if the case was in contact with steel for a time. Pretty unlikely because most people leave practice ammo in the original container and don't leave a round in the chamber for weeks on end. I also assume the aluminum is coated with some kind of protective toxic waste so this is close to impossible.

[Seismic Sam]

Please publish a 900 pixel wide picture of the case head. From what I can see, the lines on the case head look like extreme high pressure to me, but the picture is two low-res to really tell.

And I am confused!! Why would the front (which means case mouth area to me) be the area to normally blow out when it's the rear of the case that is unsupported?? How do you get a case mouth to blow out if it's all the way up into the chamber?? (Unless it's a Tim Warner gonzo load where the pressure is still up as the case comes back out of the chamber, but I'm making wild guesses here to try and figure this out.)

And Tim is right - that case looks really messed up. The case web in the primer area is GONE completely as well as the primer, and if the gun was out of battery you would think the pressure would just blow the primer out of the case. In this case, however, the pressure took out the case web itself. Leads me to beleive this was a detonation, and maybe a weak primer did the old partial ignition thing and then the smoldering powder and explosive gases it generated all went together.

[DeanC]

It does look like the bolt face has imprinted itself on the case.

[clemmac]

Please publish a 900 pixel wide picture of the case head. From what I can see, the lines on the case head look like extreme high pressure to me, but the picture is two low-res to really tell.

This the best you'll get, I even needed to borrow my wife's camera