Wasn't able to hit the range as noted, but will try to go this weekend. I have enough blue box 77 gr BH ammo to shoot a 10 and an 8 shot group. I also have some 69 gr BH blue box ammo, as well. I don't know how much of this I have off hand, though. I may shoot some more PRIVI, if time allows.
Like I stated above, I think that the upper is shooting pretty darn good considering it's a LWT CL barrel. I will more than likely use this upper for the CSAT course I will be attending toward the end of the year. On a side note, I feel that the rifle is a bit "cramped" with the standard HGs due to the carbine gas system, so I will probably have ADCO shave the FSB so I can put on the Viking Tactics Alpha rail that I have. I like the way my middy Noveske upper feels, so I want to replicate that with this upper.
I don't have the complete AR6720 rifle. The upper is on a Stag lower with a Geiselle SSA trigger and Stag LPK. I may buy a Colt lower, though, just to have a "complete" Colt rifle.