Well, I personally had a blazer 9mm in a CZ75b that the case split all the way down almost to the web.
It was at the 12:00 position, sprayed some burning stuff in the air when the gun unlocked (I thought there wasn't any pressure in there when the gun unlocked, but I guess I was wrong!), and the sound was much different than normal.
The case extracted, ejected, and landed on the ground, I saw where it landed, and examined it more closely, may still have it somewhere.
No harm done (Had eye protection).
Had the split been lined up with anything critical, something could have been broken, but nothing was in my case.
Out of thousands of blazers in many different calibers, that was the only failure I've ever had, and I guess it wasn't even really a failure, just could have been.
It certainly wasn't what I expected.
I reload 9mm now, or shoot WIN white box.
Still shoot blazer 10mm in my G20 (so I don't wreck my good brass), and a little .45 here and there when I get too lazy to reload.
Still have a partial box of 357SIG blazer ammo, too bad they stopped making it. I bought a lot of it in 357SIG, loved it. It forced me to take up reloading for 357SIG (When they discontinued it), so I guess it wasn't all bad.