Hi guys, picked up this new HK MR556A1 at the fun show over the weekend for a very good price. Have not shot it yet, but I went over it and compared and contrasted it with the DI AR (Noveske N4 Light Carbine is used here). As you probably already know, the HK MR556A1 is the civilian modified version of the HK 416 used by our Special Forces. The instructional pics are pretty self-explanatory. Typical HK, the rifle just feels like a quality piece. It is a little on the heavy side, at 8.9 lbs with empty mag. Those who want a lightweight carbine can just forget about it. Those who still want one can breath a sigh of relief in knowing that the HK upper will fit onto a regular AR lower, so it can use any polymer mags that have the top rib that interfere with proper sitting inside the HK lower. So, whenever HK starts selling the upper, you can get it and slap it on your favorite AR lower (see the bottom 5 pics). Enough with words, here are pics. Enjoy.