Boy, your going to regret that question. There are so many one holed internet groups on this page, its silly.

Seriously, realistic group consistently over and over, you should be able to pull off 1.5-2MOA easily with most ammo, decent gun and decent scope. Thats around 3-4" groups at 200 yards off sand bags. You play around and try different ammo, you could lower that to 1MOA to 1.5MOA or 2-3" three shot group at 200 yards. And alot of guns out there can pull off subMOA. Not unusual with some load development or finding just the right ammo. But factory ammo changes, and so does groups.