Home Forums Hunting & Shooting AR and Tactical Rifles Reasonable accuracy expectations from a 16" WOA barrel?

I have a Rock River arms Lar 15 with a 1 in 9 twist inch barrel, with 25 gr Benchmark and the Sierra 52 gr BTHP match bullet I shot a group that measured 1.9 inch at 400 yards. Same load shot a 100 yrd group that measured .290, I don't know if is true but I was told that Rock river uses Wilson barrels.