ORIGINAL: HighDesertWolf
im looking at my 03-a3 which basically has the same bolt design it will push feed singles. my guess you might have a serious head space issue thats causing the rounds to seat too deeply in the chamber and the bolt is stopping just short not allowing the extractor to slip over the rim.
NO rifle has a firing pin long enough to fire a cartridge with THAT serious of a headspace problem! However, this situation does call for a headspace gauge check by a qualified person! Low pressure can also cause the primers to back out, but this should not happen with standard factory ammo....