Over-engineered? Yes. But they last forever. Some years back, I bought a bunch of “rescued” AK mags from the Balkan conflict, some in what appeared to be really bad shape and with dirt and even rest of vegetation inside. Some naval jelly, elbow grease and Krylon later I had a whole bunch of perfectly functioning AK mags. Only two of them were not recoverable and that was because the metal of the body was out of spec. Still I ended up with 2 spares sets of springs, followers and base plates.