piece onto another the hopper top body 22 includes a panel 50 which forms a floor of the unit and causes paintballs to flow into the feed opening 30 fig1 2 and fig3 show the closure panel 34 as being a sliding panel which moves to one side to open or close the feed opening 30 a pair of raised catch pieces 60 can be attached to the copper motor base 12 and engage the closure panel 34 as the hopper top body is slid into place obviously other physical mechanisms for opening and closing the closure panel 34 are also possible one possible mechanism is for the hopper top body to snap into place on the motor base and when snapped into place the closure panel would be opened either as a result of being fully engaged or by an activation step of the user such as by moving a tab of pulling or pushing a tab to open the closure panel fig4 shows an embodiment of the invention in which the hopper base 12 does not use a motor but allows paintballs to fall by gravity this type of unit has a larger ball magazine 62 which fits with a larger feed tube 48 other features of the hopper top body 22 are similar to other embodiments.