Some Norinco 7.62x39 was labelled non-corrosive, but turned out to be corrosive. Don't worry about it - clean the rifle, and be done with it. If you want non-corrosive x54R, get the current manufacture soft point; same with x39. There is non-corrosive ammunition available. Incidentally, if you are worried about corrosive, clean the day of shooting, and then check and reclean a few days later, just to be sure.