I'm with dolanp on this one. Bulgarian mags can be identified by the "10" in a double circle on the mag. In my experience they are a little bit tighter than surplus steel mags in the SSR85 and the converted Saiga, but they fit and function fine. Promag makes a cheap knockoff that even has the same "waffle" pattern, but we all know their reputation for reliability. If it's the Promag, then change it to a quality steel of Bulgarian polymer mag. If it's a good mag, then it might be the way the mag well was was cut out or the mag catch installed.