I too asked this question (although it was more AR-15 specific). I got the same answer that cuervo gave, DPMS. My next question was "are they a good company". A lot replied that they were not, and a small few said either they LOVED it, or said it was the same as all the others.
So if you're liking the sound of a left hand AR... go carefully and dom some research about DMPS. Here is a link to get you started.
http://www.ar15.com/forums/