I have loaded thousands and I cannot recall having one bad one. I have used Winchester primers up until recently and now I am trying Federal in my rifle loads.
Those who report problems with CCI primers seem to be using Dillon or similar progressives. I suspect it may be due not so much to a problem with CCI primers per se, but something that makes CCI primers and Dillon equipment not play well together.Nothing but problems with CCI primers using Dillon 550 press.