We reload all of our rounds on a dillon 650. Cases are trimmed on a Giraud trimmer. Brass is a mix of mostly military range pick up that we swagged and whatever else is sitting on the ground when we sometimes shoot at civilian ranges. We are not that picky since we are mostly shooting inside 100yds and are looking for combat accurate. None of our shooting is done from a bench. Anyway, here is our problem. We are unable to manually clear a round from the chamber. You have to pound the stock on the ground while holding back pressure on the charging handle. After pounding it a few times it clears. It goes into battery fine both when shooting or when inserting in a new magazine both using the ping pong. It will eject cases fine when shooting. But when you need to "unload and show clear", you cant. Now this only occurs on our newer ar-15's. When we shoot the full auto M-16's, we dont have this problem. We have even picked the rounds off the ground once we beat them into submission and checked them on a case guage right there on the spot and they are showing right on the money. It is obviously a sizing issue, but its checks fine on the case guage. I have no idea what to do. Any help would be appreciated.