Can someone please explain to me what exactly make an AR a tier 1,2, or 3. I hear some say tighter tolerances, but where is the proof? Has anyone stripped a Colt or DD and compared it to a stripped RRA or Stag to measure? Does being made to mil spec automatically make something perform better? Most modern 1911s are made tighter than what mil spec would be and perform great. On the other side some have said that all makers use the same parts, where is the proof? I have heard the opinions, I have even studied the "Chart" (hard to compare everyone if they have not provided info), I would like to hear some hard facts so I can fully understand. Thanks.