My dumb little nephew bought A Norinco SKS equipped with a dragunov style stock and 30 round MAG and a 10 round magazine. The 30 round MAG will not fit correctly or feed at all and the 10 round magazine seems to lock in place OK but we have not tried to shoot it like that to see if it feeds OK. My main question is, should the 10 round magazine pop in and out easily? On the disassembly videos on the net, it shows the trigger group needing to be removed from a factory stock before the MAG will come out. Is there a certain brand of 20 round or 30 round magazine that is known to function reliably?