Here is a topic that has not been talked about for a while, Detonation. Our local club was having it's annual deer hunting sight in days this past month. One of our regular, hard working guys who is one of the backbones of our club, got humbled during a slow time. An avid shooter and reloader of 45+years had a blow up on the last day. With his own rifle, a '03 Springfield (very safe and tough)had a round do what it wasn't suppose to do. Turned out he had a (accidental)double charge of some fast burning powder. What charge of what type I do not know at this time, will find out. He recieved cuts on his face, nose and a piece of brass in his eye that was removed at the hospital, fortunately no serious damage. And you guessed it, no safety glasses. Been trying to tell him for years to wear them, maybe now he'll listen. Don't quite know of the rifle damage. People used to call this phenomena "Detination". But as you can see, even well experienced shooters and reloaders still screw up. By the way, he uses a single stage press, no progressive. So guys, lets be careful out there for there are those that have and those that will.

"Uncontained Detonation"
It's going around lately.

That sounds like maybe he accidentally used the wrong powder. Most rifle cartridges generally use slower burning powers that nearly fill the case, it's hard to double charge. Or maybe he changed to a faster burning powder and forgot to reset the powder measure settings.