Interesting ammo kaboom today

[Lon]

After work I stopped at the range to test fire my new Combat Arms CA19 build (which is running an 11lb spring) from this thread:
https://pistol-forum.com/showthread....9-clone)-build

The ammo I was using came from a bag of misc leftover ammo I’ve collected over the years. It a mix of who knows what that includes hollow points and FMJ. I just grabbed a handful and loaded a mag and banged away just to test for function. A few mags in I get an earth shattering kaboom (ok, maybe not earth shattering, but definitely different) and the mag comes out of the frame without me hitting the release. I look down and right next to the magazine I find this little guy:



I was shooting as fast as I could pull the trigger. And I wondered if the gun wasn’t quite all the way into battery when it went BANG. Then I looked at the head stamp and noticed this:



I can’t even remember when I had FC +P+ ammo in the past. Maybe 9BPLE? The barrel was an AIM G17.5 barrel. Didn’t see any damage on inspection. I’ll have to look through the bag to see if I’ve got any more of those.

[DpdG]

Curious failure mode, usually there’s either noticeable pressure signs or obvious out of battery indicators. Primer doesn’t look particularly flattened and the hit, while not perfectly centered, doesn’t look particularly off centered nor significant striker drag marks. How’s the chamber support on that barrel?

[Lon]

Curious failure mode, usually there’s either noticeable pressure signs or obvious out of battery indicators. Primer doesn’t look particularly flattened and the hit, while not perfectly centered, doesn’t look particularly off centered nor significant striker drag marks. How’s the chamber support on that barrel?

When I get back home tonight I’ll take some more pics of the barrel and put the casing back in the barrel for some.

[BN]

I'm not familiar with that frame, but is it a Glock clone? 11# is awfully light. I had problems with unlocking with 13# and didn't go below 15# mostly. The springs need to work together and I'll guess that pulling the trigger could unlock the gun. It looks like an out of battery to me.

[Clusterfrack]

@Lon, that looks like a pretty classic out-of-battery case rupture. Glad you're ok. I'm surprised the gun is undamaged.

[Lon]

I'm not familiar with that frame, but is it a Glock clone? 11# is awfully light. I had problems with unlocking with 13# and didn't go below 15# mostly. The springs need to work together and I'll guess that pulling the trigger could unlock the gun. It looks like an out of battery to me.

I’ve been dry firing the hell out of that combo paying a lot of attention to whether the trigger pull is unlocking it. Haven’t seen any of that. Totally agree it was OOB.

[Clusterfrack]

I’ve been dry firing the hell out of that combo paying a lot of attention to whether the trigger pull is unlocking it. Haven’t seen any of that. Totally agree it was OOB.

The locking block/barrel lug plays a big role in preventing OOB firing. I’d look at that as well.

[Lon]

The 11lb spring went in the trash. Was curious how it would work, but it was a failed experiment.

Here are some more pics.





Now I’ve got 2 OOB casings to use as demos in classes. Today’s was much less dramatic than the last one.

[DpdG]

Wow I was wrong about the striker drag. Completely concur with OOB in light of the pictures. Glad it worked out and if it helps for your library, here’s my only case rupture:

[Lon]

Wow I was wrong about the striker drag. Completely concur with OOB in light of the pictures. Glad it worked out and if it helps for your library, here’s my only case rupture:

ouch. What was the cause? Any ideas? Bad ammo? I had a Freedom Munitions .223 case that did something similar now that I think about it.