Ok well it is going to be in an upgraded well mb05 with a tuned pdi chamber. I will most likely be using goldenball .3g bb's. I need to see the barrel length needed and will go 6.03 because I have had good experiences with them. I am very thankful for the nice comments explaining the theory and I know it is complicated (no solid evidence and to many variables), and I know that it is the quality of the barrel but seeing as I like prommy barrels I am all set there. Once again thank you.