Originally Posted by mista.matrix
the .693 back more versatile is the Ifit for me...?
You will get efficiency improvements by using any of the backs on the Ifit kit with your stock barrel assuming the paint isn'y .693 or bigger
. The control bore on the Ifit isn't super long so aren't able to get quite as much efficiency as you would with a barrel system that has a longer control bore. If you like the stock look and porting of your barrel and want to squeeze a bit of efficiency out of the gun than I think the Ifit would be a good buy for you.