I have a Spikes Billet upper and lower,cmmg piston conversion, wilson I think 16" barrel, tinley trigger,floating foregrip[or whatever they call it] colapseable stock, single pointsling, hell I forget the rest I'm a 1911 head, a gunney friend of mine picked the parts this thing is made of, built it bout a year and a half ago, I seem to remember m4 package or something like a chamber rated for .223 and the .556 or something like that. gonna get a eotech for it, also got troy Industries folding sights, I forget what kinda grip and prolly a few other things about it.
Oh yeah the piston conversion cmmg made it but I dont have anything to compare it too no experience with a stocker, though I do remember the floating front grip is special in a clearance way when you have a piston conversion. it does work great though. don't know anything about nikon optics and I really am new to AR's, if I remember correctly I think Indiana has a dumb law that involves a tax of $250.oo for a barrel shorter than 16" or 18" ? somthing like that, any way I got the shortest barrel I could without this Bullchit fee for nothing.
Yes I do realize you dont have to put a lot of $$ in an AR to have a good running shooter. knew that before I built it.