Nay sayers? What I wrote is not "hear say". I recently took over 100 pounds of "range brass" to the recyclers from my gun club's pistol range. Before the recyclers will accept the range brass it has to be "inspected" for live rounds. During my "inspection" I found over 100 live 22 LR rounds, most had sufficient dents in the rim but were not discharged. If I am correct the method of applying the priming compound in a rim fire case is to put a drop of wet priming compound into the spinning case, the centrifugal force distributes the compound into the rim. If the drop is a "light" drop there may not be enough compound in a spot in the rim thus causing a dud. There are billions of rounds of 22 RF made weekly so the probability is inferior rounds is high. I would expect their priming failure rate is higher than 4 in a million rounds. BTW I found one 9mm dud. Centerfire ammunition is far more reliable.