I bought two 30 round mags, two 20 round mags and one 75 round drum for my Rommy AK, and only one 30 round and one 20 round mag snaps into place in the receiver. Before I send them back, I was wondering if anyone has suggestions for something I can try to get them to seat properly? They slide in almost all the way, but the magazine catch doesn't quite click in. Just eyeballing the 20 round mags, I can't see even the slightest difference, but one clicks in nice and firm, the other comes about an 1/8 of an inch shy of passing the magazine catch. These are all unused condition Eastern Europe surplus and in excellent shape. Any thoughts?