I shot approx 40 rds of this yesterday for the accuracy portion. 10.5" (6x), 16" (6X), 22" (16X) from a bench with my normal shooting sled. 50-55F with min/no wind, bright sunny day. I'll preface by saying every time I shoot a Hornady 77gr they don't group as well as the Sierra. Best group (5 shot) on the 22" was 1.296". 10.5" was 2.591", and the 16" was 1.355". For some reason we were seeing a random flier which opened the groups up. (Maybe the sun was messing with me).
Primers were a little flat and cratered in the 22" but nothing I would consider concerning. They were shot suppressed as well. 22" barrel is marked 5.56 1:9 (TC Compass), 10.5" 1:7 PSA, and 16" 1:7 Springfield Hellion.
The cleanest brass in the pictures is from the bolt gun, and the other is from the 10.5" and 16" suppressed :Dhttps://sgammo.com/product/223-556mm-ammo/20-round-box-5-56-x-45mm-77-grain-open-tip-match-frontier-ammo-fr262-for-use-in-5-56-nato-chambers-only/