I have had only surplus gov't M14 mags,because I got them with my first M1A long ago,before the gov't decided not to trust us citizens with hi-cap. mags.In my experience,I never had any malfunction with the standard 20 rnd. gov't mags. If you bought any other type or manufacturer,and had a feed problem,then you might try a mag. re-build kit from e-gunparts (Numrich Arms). Just my 2 cents worth.:2guns: - BILL