Not sure what my serial number is at the moment, but here is a picture of my HK MR556 all set up. Have a Surefire flash hider/mount on it now though. Hoping my Surefire can Form 4 will be done in the next month or so. It has been about 6 months after all!
I used this rifle, as set up, at one of Larry Vickers' 2 day carbine courses and it was great. Boringly reliable. That sight sucked close in though, slowed me waaaay down. Still, I was the man for the offhand at distance portion of the class at least. Figure at some point I will stick one of those offset mounts on it and use a T-1 to make it good for close stuff.
I have been documenting every single round through this gun. So far 1,372 rounds and zero malfunctions. I have not been very careful about cleaning it either. I keep it lubed though. Very happy with it. Looking forward to running it with a can. Will advise on how that goes and new pics also. Heavy rifle but a very good one!