Except for the new Noveske competition barrel (which is not available yet) I would bet your DPMS barrel would not be outshot by a Noveske barrel. They are very good barrels, but they are not intended for "best" accuracy. There are a few that might give you a slight improvement, like 20% or so. If you want to get down to where you have a 1/2 MOA capable rifle, you will need a better upper receiver with a correct install of a Kreiger or Bartlein quality barrel. Putting a Kreiger on a DPMS receiver though might not get you sub MOA.