Took me twenty years of reloading to have my first squib today. I was shooting my brand new CZ P09 and in the middle of a mag dump I had a boom. The pistol locked up with the barrel stuck in the forward position. Took me a couple of hits with a rubber mallet to free it up. And sure enough the barrel was bulged. I take full responsibility for my screw up and will have to send the gun back to CZ to see if they can help me out. It's a testament to the quality and strength of CZ pistols that the only real damage was a slight bulge in the barrel, blown extractor, and a small chunk of finish off one of the forward rails. The CZ P09 is built like a tank.
The only excuse I can think of is after all these years reloading with a beam scale I used a digital scale for the first time. I think I'll go back to my slower but trustful beam!
I have pics of the damage , but do not know how to download them to the site.