I have one from Brownells. Rifle details: Accuracy Speaks di trigger group, DPMS stainless lower, DPMS lopro upper, Warn qr high rings, Redfield widefield fixed 4x scope, and EGW stainless 20" Integral muzzle brake barrel.
Federal premium 52 gr. =3/8"
Winchester walmart 45gr.hp2232=3/4"
Fed. Trophy Bearclaw= 3.5"
These are among the better average. Someday I'll get a scope with higher magnification, but I'll work with this on for now. I have'nt seen any post about this barrel, and I was wondering if i have the only one or what! Btw These groups pretty much based on 3 shots.