Which Norinco mags?
There are two basic types: The internally limited type, grey park, parked follower - these are basically MILSPEC and have worked in every rifle I've tried unless the rifle itself was bad. Sometimes these mags have tack welded bottom plates, sometimes not. They are limited because the follower itself has a long piece of metal on the bottom of it.
The second type has a blued follower and generally they are rivetted on the bag body to limit capacity - most mags now sold are this type. They are usually a tighter fit in most guns and the follwers are NOT milspec. When I get these mags, I try to look for GI followers to replace the blued ones - they aren't reliable and don't allow the BHO to function.