I'm not sure about Norinco primers. I did about 5-6K of 9mm recently (see linked thread for breakdown by headstamp) and only found a dozen or so "two holers" in all of that. I find them when they won't decap after a few tries and I look into the case. When I do get one I just toss it into the scrap brass bin...
http://thefiringline.com/forums/showthread.php?t=506489