Yes it does. In fact, I think that's part of the name. Like a carbon 16 or something. Is there a particular reason that the carbon lower is undesirable?
Don't know about the carbon lower, and my Bushmaster is from before they made those---but about Bushmaster in general, I love mine. It feeds everything (EVERYTHING!), runs all the time (even back when I only cleaned it every 5000 rounds), and is more accurate than I am (note: that isn't hard).
I use mine for shots from 5 yards out to 300. No, it isn't a precision rifle or anything for those who will shoot it at 600+ yards (maybe it could be? never tried) -- but for that 0-300 range, it is spot-on. I used to shoot irons, had a 4x on it for awhile, now I've got a TAC30 1-4x illuminated on it, and I love it. Use it in Multigun, among other things. (I have their Shorty AK version.)
Only thing I ever had to do to it was put anti-walk pins in the trigger assembly.
Bushmaster makes good guns.