When setting up the powder die... The drop tube is put in and when you mount the powder hopper/dispenser DO NOT completely tighten the two setscrews to hold the powder hopper on the die. There should be a little play (up/dwn) but still in the groove. I finger snug but not crank on it with an allen wrench. This small movement allows the drop tube to better align and the belling to be more consistent if your cases are not radically different in OAL.