I’ve had one go off. Three or four months ago. I expect my hearing to return soon. I’ve crushed, inserted sideways, and even upside down. Never an issue getting them out and even reusing most of them.
Then I started converting .223/5.56 to .300 BLK. Didn’t get all the Crimp out of a case. Seemed a bit hard going in so I kept rotating the case looking for the sweet spot. No significant change in pressure on the press, but I apparently hit the right spot the wrong way. Bang! I was so startled I didn’t really know what happened. Wife yelled out from downstairs...what was that?
Now I have a Hornady Swaging Die. Works really well...but I am still quite jittery priming converted brass. If anything feels a bit off I throw that case into the rework bin.