I shoot more than average, so unsurprisingly I have experienced more true duds than most. I will say the nearly universal culprit in semi-auto failures is not seating the primer deep enough. It will take a decent dent and not go off, and I’m not sure why (I have a theory, but that’s all).

As far as true duds, I average maybe one or so a year. Hardly ever. Primers are one of the most reliable things I know of.