Sorry it wasn’t crushed?
Literally ripped in two?
Was this a new round or reloaded an unknown amount of times?
Reload. Came out real easy. Put the barrel in the lathe and polished the chamber up, try again.
Wow !!!
ok, unless you bought new and reloaded it may have had a long history and reloaded many times over.
With reloads the concern is Glocks don’t have a supported chamber. lots of opportunity for stretching the sidewall.
If you don’t know its history it could be lengthy and was due to fail, happily in this manner and perhaps it will be the end of your issues 
No glock bulge but no idea how many times fired. Small primer. I have some large primer going to load up and give a little more crimp, this ammo I loaded for the 1911’s the carbines seem to feed better with a little bit of roll.
10mm?
Not sure I’ve heard of that
Is there a method used to reshape those by re-loaders?
How can they be sorted and dumped dependably, I see many where the case has a soft curve vs obvious bulge
Some handloaders spent the money on a roll sizer, or buy roll sized brass. That is a really good way to do it, 100%. I inspect and case gauge. I’ve shot tons of 40 and 9 over the years, never had an issue, but buy the “once fired roll sized” bulk still have several thousand of ea in the shop. Shoot 45ACP until it splits, same with 44, 45 Colt, other revolver calibers. 308 wears out the fastest, 3 loadings and need to anneal. And primer pockets get larger. They take a beating in the autoloaders.
I wonder how many times that particular case has been reloaded?
Welcome, have you ever seen such a thing?
No I have never seen one do that I have seen bulged,cracked ,bulged primers, bit not that.
I’ve had blowbacks, DI’s, and piston guns rip brass in half. Not often but it happens. Never had it happen in my 10mm 1911 pistols.
Brass didn’t look bad when cleaned and polished before I loaded it. Bought some on gunbroker and had some new that I fired through the pistols. Such a long time ago don’t know anymore which was which.
Find out if it’s a fluke or not, loading a couple small batch’s today and maybe off to the range tomorrow. I have found some cases will only hold 15gr #9, some hold 15.6gr to bottom of 155gr XTP. I like loading #9 same as H110/ W296, snug to the base.
Loaded some more 10mm, and pulled / reloaded some that were a little out of spec. Blazer is the small pistol primer brass, I can get 16gr AA#9 in those. Accurate load data max the 10mm with the 155 XTP at 15.9
I can get 15.7gr in the Aguila large pistol primer. A little over 15 in the Federal large pistol, same with the Sig large pistol.
See how they run. Bet the 16" barrel will add several hundred FPS.
Look forward to the results, may need one of those 16" barrels if so 
10mm day at the range
The Lightning managed to cycle through about 6 rounds before it ripped one in half.
I think the bolt is moving enough before the bullet exits the barrel, pressure remaining high enough that the brass doesn’t have time to deflate. 1700 fps + with 15gr powder compared to 1490’s out of the 1911’s with 15.7 gr.
Need to get some more mass or download.
Or drill a couple popple holes in the barrel to help lower pressure.
Also had issue with Thor’s hammer, chewing up brass due to bent ejector.
The ported longslide performed nicely.
Ordered some new starline brass. Eliminate brass as the problem.
You do have a problem that’s for sure, as to these
When I had that issue I shortened my ejector a lot, removed half of what existed I bet
Looks like you increased the speed as predicted 
Isn’t 10mm just the best
Even with the bent ejector and the smashed brass it still threw them 15 feet.
Going to replace the extractor and ejector. Probably go with Wilson Bulletproof
Have you tried a heavy weight buffer?
