On my 1911 I had a case rupture with the chambered round.
Edit: Sorry for the horrible quality on the photos. My camera sucks and I'm rather awful at taking photos.
That then detonated the next round in the magazine
Here you can see the two cases followed by the next in line
This was a 230 grain winchester loaded with Acura #5 to the Lee do not excede value
So I either overcharged it, the case was bad, or there was something else. The previous week I had a double fire that I thought was due to me not putting a primer in deep enough. And I did strip and check the gun.
Though now I'm wondering, as I inspected all the primers for today's shooting.
I also found this
Sorry for the poor image quality, but that little spec between the firing pin and the casing was found attached to the tip of the firing pin. It was either attached to the pin before and acting like some sort of extender. Which is very bad.
Or it blew off from the case that went boom and stuck to the pin. Note the hole on the primer of the ruptured case.
Very minimal damage to myself with some stippling to my cheek. So wear your damn glasses
The grips shattered. Slide looks okay, frame looks okay. I have to remove the bad case from the barrel. But I'll need to have it checked by someone who has an idea what's going on before I fire it again. I'll ask at the next blogmeet who is good to send it too.
I still have to do a full strip (of the lockwork) to see if I can spot anything obviously wrong.
I also have to take apart the remaining cartridges from the lot the kaboom came from to see what loadings they had.
I did a detail strip and found a few things that even I can tell are wrong.
1) The sear pin is bent. Visibly bent, bent to where it can't go back into the frame.
2) The firing pin block actuator is a little bit bent too.
3) Worst of all there's a frame crack.
I couldn't get a good photo of the crack itself, but it's in the back of the frame where the disconnector and sear would rest. The web of metal between those parts and the magazine well.
The crack goes the full length up to the top platform.
So as Wally says: one firearm passes, another is born.
I've stripped her down and an now in the market for another 1911.
At least some of the parts are reusable. I'll definitely get the sights swapped out and put on my other 1911.
Update2: I've weighed out the powders from the remaining cartridges from that lot. And found a couple ones that were heavy by half a grain of powder. Which is very bad with a batch that nominally was brought up to the Lee do not exceed limit.
I can see that being a very likely factor. Maybe add in a case that had been shot too many times (I have been using range recoveries). And then an out of battery issue.
Added: The out of battery issue was the occasional (twice) and non repeatable double fire. Which could have been caused by that bit of extra primer metal atop the firing pin, if it was acting like an "open breach" firing pin, and struck the primer prematurely.
In total that's where I could have had a cartridge go off before the gun is in battery and not only would it be less supported but overly hot charged. Multiple bad things adding up to a big boom.
Added Monday: Here's another embarrassing thing that's so basic I just thought to check: Round count. Based on the notes I took and the storage bags I put the parts in there were 6 rounds in the magazine and one in the chamber. I loaded that magazine with 8 cartridges. And my memory is quite clear this happened on the first trigger pull.
Thus after the first bullet was fired, the brass was extracted, ejected, and the slide came forward, picked up the next round, and then as it put it into the firing chamber detonated it without me hitting the trigger. Scary. And more support to the failure stack and how you have to do a detailed check when something starts going strange.
That seems like a failure stack.
So, stick with the starting throws, keep an eye on your powder measure consistency. And if you do any thing hot or weird with your loading measure every single case.
Wear your safety glasses. They're important and could save your eyes.
Inspect your ammo, especially if you reload. Check the casings and the powder loading.
Checking powder loadings goes double when you start to approach the do not exceed line.
Detail check your gun whenever something odd happens. A bit of debris may be in there or something may work.
Tre more lessons:
Bring a medical kit. Even for minor injuries having something to clean up with, and a mirror to check yourself out are handy.
Use a logbook. If you reload keep log of every lot you made, when you made it, and any changes in your system. Been a big help on diagnosing this.
Have backups if you can. I have another 1911 that I can use as a carry piece until I get a replacement.
Not a fun way to end a range trip, but could have been worse.
Some final notes and a solution plan:
1) When running red/hot loads check the weight of every single load. In fact use the rig to load them a bit light and use a powder trickler to put to full charge
2) Be more careful on inspecting brass. Especially for high pressure needs. Get more new brass to use for such roles. This also means scrounging for range brass is not such a wise idea.
3) Even when you think you've solved a fault, still do a full detail strip. As there may be more than one failure at work.
Also it looks like the frame can be restored with the crack welded and put to use as a dedicated 22 long rifle gun. It's too compromised for higher pressures, but that's a way to get something out of this. I also have the parts for the conversion.
Also I'd like to thank everyone at GBC for their help on diagnosing this: Phssthpok, Wally C-90_Fl and anyone else I may have missed.