It is just possible that the cause is only a dud primer amongst the millions made each week.

I have had 3 examples of pierced primers

1 8mm milsurp
1 30-06
1 .303

The last 2 were reloads, fired from rifles I shoot a lot. We are talking about hundreds of rounds through a rifle, then suddenly, a pierced primer. In these cases, I don't believe its a rifle or firing pin fault, just that one in a million primer.

Hands up if you have ever had primers without the anvil in it, or no compound in it.
Not me personally yet, but its happened to friends and the above was found upon examination.