I am learning some interesting stuff in this thread, and I don't want to take it off topic, but I am going to make a comment on a theme that matters to me.
I am a Range Safety Officer at my club, and I spend a lot of time telling people to put their safety glasses on. And reminding people that everyone anywhere near the firing line has to wear eye protection, even if they are not shooting. Most people are pretty cooperative, but I do get some comments about "being so uptight." Mostly I just say "those are the rules, I didn't make them."
But occasionally, when there is more time, I say "if you are shooting without eye protection, you have probably never seen a gun blow up." And I tell the story of how I have seen guns blow up twice. Both times were pretty minor, but still enough to drive home that we are messing with 30,000 PSI of pressure. And when that pressure is not properly contained, or some circumstance causes an over pressure many times greater, then very energetic chaos ensues.
I wear eye protection any time I am near an active range, and this thread is a good illustration why. In some ways, it is a testimony to modern manufacturing that the possibility of catastrophic malfunctions never even occurs to most people.