Update 6.5 GRENDEL I have now shot the Hornady Black 123grn ELD and the 123grn SST out of this upper both shoot under 1'' at 50yds and have the same point of impact. I killed a deer with the 123grn ELD this season, the 6.5 performed great! I think this will be my newest favorite cartridge/gun.
6.5 Grendel shipping was fast 5 or 6 days from the Saturday that I ordered on, and I had requested a different handgard be installed (the 15'' keymod) they where eager to accommodate my request. I like the nitride bolt carrier group, and have nitride treated all the AR bolts I have. The handgard fit is good, centered at the muzzle end somthing that I notice if its off center on long handgards on other guns. It came with the standard birdcage flash hider, the picture shows optional accessories. I shot 116rds thru this upper so far, with no function problems at all, ejection of spent casings was 3 feet out at the 3:00 position in a nice 2 foot area. I have only used Wolf ammo so far until I can get some more accurate ammo, but I did get a average of .78'' 3rd groups at 50 yards, but when I fired 10rd groups they increased to 3-4'' most likely due to barrel heat as this appears to have a M4 profile and not the heavy barrel. I plan on using this for hunting(16'' is legal in my state) and mid range shooting so the M4 profile dose not bother me that much.I am sure that one I get some Hornady ammo that groups will be more consistent. I am glad I made this purchase and if I need a AR-15 upper again I will look to ACME first.