My first upper was a fully assembled A2, probably just like most people on this list. I'm am in the process of getting together the parts for a second upper. I already have an RRA upper, a DPMS standard length free float tube, and so I want a 20" stainless barrel without stealing and selling one of my grandchildren.
What are your favorite barrel suppliers? I will use this rifle for shooting out to 300 yards. (Whatever that is in meters, klicks, or any other euro stuff.)
They have several White Oak stainless barrels. Very nice, very accurate, and won't break the bank.
And damn good people to deal with!