07-03-2012, 10:11 AM
As Stokes and others have suggested, I'd go with the lowest hanging fruit first and try lubing bolt and carrier thoroughly with Slip 2000, frog lube or good quality light oil-some even use Mobil 1. Next try to progressively open adjustable gas block in 1/4 turn increments till you get a round to eject and feed next properly. What weight buffer and spring are you using? If you're unfamiliar with AR's, I'd leave feed lips alone til you've resolved first two protocols-you might just as easily create an issue as resolve one. There is a wealth of wisdom to draw from here and advice if freely given. The "search" function is very useful, as we've all had issues requiring guidance, at some point or another. Post up your results.