Well, it finally happened to me. I was loading .45 ACP LP brass with Federal LPM primers, had one apparently get in the disk upside down (?!) which I can't figure out how that could have happened. I use a RCBS flip tray and manually pick up the primers with the Dillon primer tubes, not sure how I could have missed one as I am pretty careful. The primer was seated in very clearly upside down in the case, no resistance that was unusual until the bang. Fortunately I only had about 10 primers total in the press, but it was still fairly loud and scared the poop out of me. Upon initial inspection, all primers in the disk and a few in the tube went off at the same time. The low primer plunger left it's top in the OSB of my upstairs decking, I had a .45 case for extra weight, so that is embedded up there as well I suspect, or it / they bounced who knows where. I didn't dig into the R30 insulation in the garage to look yet, I can see the hole they made in the insulation. Found the plunger rod all corkscrewed and broken, aluminium primer tube has a couple of deformities on the bottom, had at least one primer in there. Shell plate and primer disk appear OK, not sure about the priming assembly, I took it off and put it back on to check the shell plate and primer disk, not sure if it is damaged or not. Glad the press was not fully loaded with primers! Sent Dillon an email, will call tomorrow since it is Labor Day today. Glad the press' design did it's job, no injury to me, no major damage. After my reading about Federal primers being 'soft' and easier to detonate, I am not sure I want to use them anymore. My luck with CCI for 4k rounds has been fine. After a lot of reading the 650 is known to have this happen infrequently with most incidents happening with Federal primers, but also with some other brands.
Be careful! I am upgrading my safety glasses to whatever I find that seems the most bomber, tough I can find.
We'll see what Dillon has to say, not really sure what all I need to replace apart from the obvious.
Jason