I shot a 5" group for 5 rounds at 400 yards with a CL 5.56 Chamber 16" mid gas 5.5 pound AR on Tuesday. My 18" 3Gun match rifle is about 3" with the same ammo. Built right and tuned correctly, nothing wrong with a 16" gun. But same ammo, I split the 18 faster and I transition faster with it as well. Enough that at the end of a 30 round rifle stage, it might amount to 0.42 seconds.