I just got my norinco m14 and for some reason it wont chamber a round. The bolt will pick the round up no problem but when it comes foreword to chamber the round it sticks just before twisting in and locking down ( if i smack the bolt handle it will puch foreword and seat properly). I have fully disassembled it and cleaned and re oiled everything but the problem continues, has this happened to anybody else and if so how can i fix it ?.