Sounds good. How many mags do you have and what kind are you using? Are you filling them full and cycling? Try some of those milspec mags I gave danny and see if they help out. Bad mags will do that exact problem you are mentioning. Another thing as well i have seen is to check how sharp the feed ramps are going into the "star chamber" - sometimes they will have burrs on them from machining that for some odd reason pass inspection.