I have a batch of CCI 250 that has occasional misfires in all guns I have used them in. Several other primer brands never failed to fire with the same guns and loads. Bad primers do happen.
If there is an assumption to make, and until known otherwise, it's NOT BAD PRIMERS.
CCIs are thicker, and my testing shows best CCI results with 4thou of seated crush (-vs-2thou for Feds), to better sensitize them.
My observed failures have consistently showed up with CCIs first. Things like lower temperature shooting, or a slip of firing pin in it's cocking piece.
Keep in mind that primer firing is more than deep indentation on striking, if that at all.
To test this, I once smashed a primer fully flat in a vise. It did not go off.
Instead, there has to be enough
relative speed of strike, with only sufficient striker mass/force, to set off the explosive pellet.
Relative speed is produced with a sum of striking components and primer movements.