So I think I have this narrowed down to the extractor. Yes, it jams on semi-auto. It jams with both the 20 and 30 round original issue "LE/Gov't use only" magazines.
.223 cases ejected from an AR we shot today show "claw marks" from its extractor, and cases from my AC show only faint "shiny spots" where the extractor passed over the lip of the case, but no evidence of it solidly grabbing the case "groove".
If a new extractor, due sometime this week, doesn't fix this, anyone here interested in a deal on an AC 556 with accessories?
Last edited by Motoquebrado; January 14, 2012 at 09:51 PM.