Hey guys, anyone know what the little screw above the velocity screw is for on the JCS powertube for the ABT. The little screw I am talking about is right on the powertube itself and is right above the screw where you adjust your velocity. Thanks. Also what all controls the velocity of the gun. I know the velocity screw on the power tube and drive spring (too tight or too loose) can make differences. Can any other component in the internals control the velocity.