I have a buddy that brought up his brand new Bushmaster Predator and its the only AR I've ever been around that is a true single shot. We disassembled it and cleaned it an lubed it 3 times. The most we ever got it to shoot in a row was 3 times. We tried a dozen different mags, and about 6 kinds of ammo. Sometimes it would eject the empty, sometimes it wouldn't. Not real sure what its deal is, he was taking it back to the dealer today and seeing what they had to say about it.