I've had light strikes that didn't go off, but it wasn't the primers. It was the gun.

It's always possible there was a bad batch of anything made. I have been handloading for years and using CCI with great success. I chose CCI because I shoot hotter loads on occasion and had seen softer primers flow back. I even starting using small RIFLE primers for my 357 Maximum because they were even harder. So harder is neither bad nor good.

This year I was using a .32 revolver with a light trigger and a light strike and getting failure to fire every 2nd round, using harder CCI. Even a second strike or third would not ignite them. It was definitely the revolver that was right on the edge of too light of a hammer fall. I switched to a soft Federal primer and was able to get consistent ignition without tuning up the revolver.
I don't like building custom ammo for one gun, so that revolver will get worked over eventually.

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