[Ceemack]

I've used CCI primers for about 20 years without a failure.

I have had numerous failures with Winchester primers--about 1 in 8 or 1 in 9--but these were limited to large pistol primers used in a Glock 21. There's something about the design of the WLP that doesn't play well with the Glock striker.

No problems with WSP or WSR primers.

 

[Ceemack]

Nothing but problems with CCI primers using Dillon 550 press.

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.

This is the same kind of thing I see with Winchester large pistol primers in the Glock 21--I don't think there's anything inherently wrong with the WLPs, it's just that they're not a good match for the Glock.