Shootingstar, I think somethings can't be explained. I have no idea why my friend or I haven't had pierced primers. I normally shoot a half dozen different guns each year, comprised of sxs,o/u, pumps and autos. And I shoot a lot. I certainly could not put my finger on it unless it might be changes in the metal used for the primers. They have always been much cheaper in the west and literally most clay shooters here use them. I have never heard anyone here talk about pierced primers with cheddite.
I don't question that it has happened though.
Lenard