UPDATE...I went back to the range with the new korean mags, it started out with nothing but problems. The rifle want's the factory mag or it won't chamber or fire correctly. I forced 50 rounds through it with the new mags and it finally started accepting them, another 50 and it's good to go. The M2 mag catch made a big difference, it keeps the mags rock solid when inserted in the rifle. I also added the kensight adjustable rear sight and it works wonderful and the adjustments are very easy. I'm going to strip it down and give it a good scrub and cleaning, I figure another 100 rounds and the rifle should be broken in fully. They seem to be a bit rough in the beginning but with a little time and patience it all worked out well. I'm very happy with it.