When Glocks first came out, there were a lot of stories about Glocks going Kaboom, esp. the 40.
A KB is basically a reputred case head.
I can't say that it never happened, I'm sure it has, all I can say is I am yet to see a picture of a Glock with a KB. I personally feel you will never see a KB with a factory loaded round.
The only pictures I've ever seen of destroyed weapons were due to improper handloading. Which is why it is so important to be careful.
I have seen pictures from the 50s of blown revolvers, but they were from the triplex loads from the early days of the 454 magnum. They were fired from a rest so no one got hurt.
Best regards
Joe