According to this, a few M16A3s were purchased by the US Armed Forces, but if their usage is so limited that the average soldier isn't aware of them, I guess it's a moot point.

Bullpups are neat and all, but one thing I don't think is considered much is their ability to be deployed as a bludgeon. How are you supposed to strike someone with the butt or muzzle of your rifle if it's a bullpup? The ergonomics don't lend to that, in my opinion.

Tactical Response's DVDs don't display any select-fire rifles. That's why I didn't say "assault rifles". It defines combat rifles as was posted above. Battle rifles certainly have a combat purpose, but they're not really covered in the DVDs, since their purposes are slightly different than the purposes of a combat rifle, as defined by the DVD. Tactical Response's DVDs are about relatively close-range combat, or at least, that's the message I got. Emphasis is on acquiring and firing quickly, transitioning to back-up weapons and such. If they were to make DVDs on battle rifles, so to speak, I imagine more emphasis would be on setting up for long-range shots, and taking down multiple targets at long range in quick succession.