All advice is not to necksize for a semi-auto and I've adhered to that with thousands of reloads over the yrs.If you are going to necksize I would suggest that you trial chamber every one of your necksized cases before re-loading and firing them.This is a check to ensure that the case will freely and fully chamber due to the possibility of the case shoulder not being setback by the neck resizing process and also as a check that the radial dimension of the case is not too "fat" to fully chamber.Remember that a semi-auto bolt does not have the same camming power of a bolt gun to chamber an oversize case.Do this check with the bolt stripped and the op rod spring removed. Why do I suggest this? Well, I have experienced one out of battery detonation due a resized case being too wide in the radial dimension to fully chamber,and I do not want to repeat the experience.As a precaution I even trial chamber every round of FL sized brass before reloading it for my M1 and M14 types.Now maybe the Norinco product is a bit more forgiving due to its more generous chamber dimensions which are often discussed in this forum.BTW I am a great believer in necksizing and do this extensively for my bolt guns,but not for a lever or semi-auto.