I have had the 16" pencil 308 barrel since it first came out. Now shooting it in my 3.9 pound (without scope) AR308.
My first ultra light AR308 used the Faxon 18" mid weight back in 2015, got that rifle down to 5.1 pounds, that barrel also shot under 1 MOA but POI did shift some compared to the pencil barrel. Pretty amazing the 28.35 ounce pencil barrel can be so accurate at 16 inches. I only shoot factory ammo.
I have been able to get sub MOA at 100 yards from 175 SMKs, 168 SMKs, 130 Mk 319s, and lately the 110 grain Varmageddon's. Some 5 shot groups have been half MOA!
I usually shoot for accuracy using a Leupold AR 6-18 power scope.
But even when I shoot fast, the POI doesn't shift much, although the group size opens up to 1.5 to 2 MOA.
Just got a Faxon 18" Match 6.5 Creedmoor barrel @ 39.20 ounces, my goal is building a sub MOA rifle @ 400 yards with rifle weight under 7 pounds. Actually I am shooting for under 6 pounds as I like my rifles about 5.5 pounds before scope.