I swap the 6.08 280mm stock to a prometheus 6.03 280mm inner barrel in my CQB M4 and grouping is a lot better and gave me a very small FPS increase. About 5-10 fps.
But HOP UP is definitely an important factor for accuracy and range.
P.S. Not sure about the range. CQB games did not gave me enough space to check long range shots. I believe it did not change much.
Now I believe that you will not be happy whit a CQB carabine for long range outdoor shots. A tight bore on a small length barrel will not give you the range precision needed for outdoor games that is for sure. Longer the barrel is the more long range accuracy you will get.
Last edited by Capt.Flan; February 28th, 2009 at 20:09..