Guys, not to jack this thread, but as a sidebar, I would imagine that over the years, I have fired 100's of thousands of primers. And on the few, very, very few, in fact, failures that I can call to mind, I can't recall one where the fault could not be traced to a mechanical lack in the piece.
Even with that, I can only recall a few failures over a course of almost 60 years.
In my opinion, if you are having failures to fire with one brand of primers and when you switch to another brand, the problems goes away, you haven't corrected the problem, merely masked it.