Lofty,
As you basically said,most,if not all problems can be traced back to magazine issues.

I think that when they started to go away from the 7 round mags and started to increase the round count to 8+,things kind of went down hill from there.

I think I have about 8,seven round magazine that have shown no problems. Two magazines from a highly toted manufacturer,are 8 rounders and have given me nothing but trouble.

Just my experience.

Wayne