Cal,
Yes, exactly, AR = Armalite.

As far as the Bushmaster quote, they have had that for awhile, many think to keep their own legal folks happy. There are two camps on the M16 parts issue. The
"no way" guys and the "look at the rulings" guys. Personally, my guns are stock and they will in all probablility stay that way. Some folks use different parts for different reasons, mostly competition guns. There were, and still are, ARs being shipped that you will find M16 bolt carriers it (so I am told) as well as triggers.

Basically, it all comes down to the function of the gun. If it functions as a machine gun, baaaad. If it shoots one time per trigger pull,,, good. This is an excerpt from an ATF ruling (important part is CONTINUES TO FUNCTION);

"....accompanied by the removal of the other internal M-16 parts to
ensure that the rifle will no longer fire automatically. As stated
above, failure to remove these parts will result in making tax
liability should the AR-15 rife continue to fire automatically.
Indeed, possession of such weapons would be in violation of the Act
and they would be subject to seizure and forfeiture. Of course, if
the AR-15 rifle no longer functions automatically after removal of
the auto-sear, the rifle no longer constitutes an NFA weapon. In
this regard, the Bureau has held that an M1 carbine converted to an
M2 capable of fully automatic fire and then restored to its
original condition as an M1 capable of only semi-automatic fire is
no longer an NFA weapon. See Chief Counsel Opinion No. 21032,
dated June 10, 1970.

All that said, there is no real advantage, either through cost of funtion, to use M16 parts. So, one would be "better off", advised is the government term, to not use M16 parts in an AR15. I don't have any reason to poke the dragon in the eye, so my guns will remain stock and any builds will be done using kits from the big name suppliers like DPMS, Bushmaster or Rock River.

Hank