This is for all the so called experts that call this story BS. I had a 06 FFL to manufacture ammo many years and we switched from Federal primers to CCI primers in my old C&H Autochamp progressive machines after the yellow dust left from the Federal priming mixture exploded when I was loading a primer magazine. Federal primers are the most sensitive that is why they are packaged in such large boxes. About a year ago I had the same thing happen that Earl did with a Federal small pistol primer I about wet my pants. Just the primer went off all the powder was left unburned in the RCBS bullet puller. I posted here on this forum when it happened to me and several people commented they also had it happen.
The primer "dust" will explode and I know a guy it happened to. I think, somewhere in the directions/safety instructions for the presses with a primer feed they recommend cleaning the priming tube/system regularly.
One of the guys at work was big into the "action" pistol shooting/competition world several years ago. Had a custom .38 Super he competed with. One day he came to work with his right hand all bandaged up. The primers had stopped feeding. He pulled the tube loose and it was really dusty with the primer dust. He shook it and got some primers out but still couldn't see through the tube. He, holding in in his right hand, rapped it on the edge of the bench top and it exploded in his hand. Took off most of the last digit on one of his fingers (ring finger I think) and cut up the rest of them, the thumb and the palm of his hand (palm not so much, but still bleeding and small pieces of metal/burnt priming compound in them.)
The material is very sensitive to impacts.
I stopped buying Federal primers years ago when they made the 100 primer trays so big I couldn't dump them in the Lee hand priming tool tray anymore. Probably did that for "separation" between primers in case one, or more, were set off by something. CCI, Remington, S&B and Winchester still put there's in the small boxes I can dump easily into my priming tool trays.