I loaded my first .223 rounds yesterday with H335 and Wolf .223 primers, lot 9-09. Out of about 20 rounds I had one misfire in my stock AR -- three deep hits and no luck.
Pulled it down afterward, and found that the primer fired, but there was no burned powder. I could see the anvil marks inside the primer hole, so I'm quite sure the primer was seated. I don't believe the flash hole could have been plugged -- this is once-fired, processed LC brass, and I resized with the decapping pin in place. I have 4,000 more primers (hope I don't get too much practice clearing misfires!).