Originally Posted by Colorado4Wheel
Those are expanded not bulged. They will probably drop right in the factory barrel and you can probably spin them in the barrel. Try it.
If they don't spin they have a little guppie. You can't see it well in the picture. You may see it different because you have held them and see it better and know what to look for in the picture. But to me those look OK except the primers look flat but it's not easy to see.
That is just how Glock 10mm brass looks. A little barrel shaped.
BTW, I would guess you had a overcharge. Maybe not a double charge but a overcharge.
Are you using a Progressive Press?
I owe u an apology. I responded to your idea of spinning a fired case in my bbl by stating I'd never have even been able to fit one in the chamber in the first place. I was thinking case gage, not bbl. sorry :-(
So, I tried your suggestion. I CAN plop the fired cases in the chamber. They turn freely. It brings me back to my original thought that the cases looked normal. I believe an overcharge got by me, as a few have suggested.
Thanks a ton for all your input, everyone. I've learned a few things and I hope this thread is a cautionary tale for those looking to reach max loads and beyond.