These are some really good responses. While out getting my 5.56 receivers, I checked out a NA 9102 CA MA National Match. I, as nieve on this subject as I am, really dont know what I'm looking at. Listening to a salesman is conflict of interest. i liked it because it had longer barrel. The way I understood it, it was a step up on accuracy from the standard. But then your straying from the way gun was originally designed. ? I've always leaned towards extra weight and length to a certain degree for accuracy. I dont think I'll get into the DPMS, but am now interested in find out more about the rock river version. Its a bum thsese arent as versatile as the ar 15s. So I'm all ears on any more of this. ??