Very common, several threads about it if you look back.
Norinco (and Barnaul) 223 and 308 have NATO spec primers; thicker and harder cups. Light striking firing pins in civilian rifles sometimes don't set them off. You can buy an aftermarket spring for your bolt made by Wolf from several retailers (I believe Canada Ammo stocks them for many rifles).
Every single Norc or Barnaul "dud" I have been given by people fired first time in my Norc M305 before I sold it. It isn't the rounds, it's your rifle.