Originally Posted by minimag03
Excessive drag that slows down the ball enough to cause a loss in efficiency/velocity happens at an underbore of .008+. The OP said he wanted a Bob Long barrel, and I believe the smallest single bore barrel he offers is .685. I don't know about you but I haven't seen .693 paint in 12-13 years.
To clear up the confusion, I was speaking to one piece barrels with a straight bore in general, not specifically to the stock G6R barrel. The .008 number is also where any
barrel will start to cause excessive drag on the ball, and I believe was done using the TechT iFit kit (if we are referencing the same Punkworks test). Once you get past the ideal control bore length of around 8 inches, you start to get excessive drag on the ball when underboring. The drag doesn't have an enormous impact, but for those wanting to get the absolute best efficiency, you still want to go with either a two piece or step bore that has 8 inches of control bore. The optimum bore length can also vary some with the type of marker used.
For the application of a stock barrel, the stock G6R barrel is superior to a two piece. The .685 bore is an ideal all around bore for todays smaller paint, and the straight bore allows the ball to continue to accelerate with even a looser bore fit.