Well...
I couldn't get the link you posted to produce anything useful, but if your talking about their mod4 (M4) uppers, then you might want to consider that they are a little bit of severe kick-ass in a can. (actually, it was a triagular box....but i digress) They unfortunatley have chrome-lined M4-profile barrels with the M4 feedramps. For some reason, they T-mark the uppers, the finish is this dark even flat black. The twist is 1:7," so you can use that shitty 77gr, OTM if ya want to, or just stick with the always drab XM193 as well. My old RASII snapped right on it, and it rocks with it. Total disappointment I tell you. If you've got one on the way, just go ahead and forward it to me for proper disposal.
-just incase any of you have no sense of humor.... THEY KICK ASS!!!!!!!!!!!!BTW, the upper T-marking was highlighted be me with Crayola Brand "Tactical HK-safety white" Its a little sloppy in this early 9/13/04 picture.
Tex78