I would think with the heavy barrel you can expect sub-MOA groups, but you will still have to match the ammo to the gun, just a good excuse to shoot it a lot! I had a similar set up in an Olympia Arms gun, it was good for MOA, but no better. The latest AR I have is an Oly Match lower (GREAT trigger!) with a Del-Ton flattop upper, and this little bugger can SHOOT. The biggest limiting factor is me and my over-50 eyes, but I still managed to get three shots into .27" at 200 yards last week. If wish I could do that all the time, but it was a fluke, the average at 200 yards is about 1.25". Careful handloading helps.
Papajohn