. . which seemed like a reasonable and safe way to proceed. WRONG! , I clearly missed something, got distracted…. Still don’t know what specifically happened . . .
My only oops was that I also failed to charge a case. In my situation, I was batch loading, but it was basic range ammo. So as I was adjusting my charge weight on the hopper, when I got "close enough," I'd pour that charge into a case (rather than back into the hopper), make the minor adjustment on the hopper, then weigh the next charge . . . repeat until the hopper was set. This meant that I had 4 already-charged cases (out of a block of 50), and then I went to go charge the remaining cases, and evidently I started with case #6 - so "5" was missed.
But even with that mistake, that still means that I failed to do a final level inspection before placing the bullets. Probably got distracted.
Yes, this was a confidence breaker. And yes, I don't charge any case now until the hopper is properly set.
I would think even without a powder charge a primer would exert enough force on the bullet to part company with the case.
In my situation above, it did not. It was a 357 Mag round, 158gn plated SWC. It pushed the bullet out far enough to lock up the cylinder (made no noise), but did not exit the case mouth. And naturally, it was the first attempted shot of a 7-round cylinder full. So that meant that the gun was locked up with 6 live rounds still in it. The RSO had a wood dowel and with my help stabilizing the gun on the bench, he pounded it back in far enough to free the cylinder. The outcome was about as good as can be, but it still sucked.
P.S. I took the remaining rounds from that batch home with me. When I got home, in a quiet environment, I shook the ammo and could hear the powder in all of the remaining rounds. By then, I figured out what I had done wrong, so I wasn't worried about a double charge. I shot them off the next range trip.