Bushmaster Varminter/target ARs

Have owned a Bushmaster Varminter for about six months. It has a 24" fluted, match barrel with 1 in 9 twist, 2 stage competition trigger, crowned muzzle, etc. I reviewed four published magazine articles on the gun. Each article reports that the gun is capable of consistently delivering sub MOA performance (five shot groups of 0.5 to 1.0 MOA) with premium commercial (not hand loads) ammunition. One article even claimed it could produce "three shot groups of 0.25 MOA with regularity" with handloads. Well, I have been trying and trying at both 50 yards and 100 yards. Using a Leupold Vari-XIII scope up to 20X I have registered some groups of 0.6 to 0.8 MOA, but the majority of groups are in the 1.0 - 1.5 MOA range. I know this is not bad for an AR, but I would have expected better. I've used just about every premium ammo, including Black Hills and Federal, in the 40-60 gr bullet weights. Using Federal LC military M193 I get usually 1.5-1.75 MOA (with an occasional flyer). Have not tried reloads. I think my technique on a benchrest is about average or better. Can you believe published reports? Does anyone else have anything to report on the Bushmaster Varminter or the performance any scoped, out of the box AR-15 style match rifles?