a high speed through the barrel 12 the gun 10 can be normally operated in various modes such as a manual mode in a semi automatic mode an automatic mode in which as long as the trigger is depressed the balls are ejected continuously as well as other modes the handle 14 is formed with two removable panels 24 a 24 b alternatively the front portion of the handle is removable and the two panels 24 a 24 b can be connected to form a single u shaped assembly the panels 24 a 24 b are removable to allow access to the interior of the handle 14 this interior is used to hold a source of power e g a battery an electronic circuit board and other accessories as shown in fig1 a typical circuit board 30 includes a microprocessor 32 that receives an input from a manual switch 34 on the handle 14 a trigger sensor 36 and a state counter 42 the microprocessor 32 also generates control signals to an interface 38 that controls the air valves and other equipment used to expel the balls from the barrel 12 the microprocessor 32 also activates an audio device 40 to provide various indications to a user typically when a gun 10 is first turned on the state counter 42 is activated the state counter can have several states each one defining a different mode of operation for the gun as defined by certain preselected parameters each of these modes is defined in the written documentation for the user the different modes may provide various rates of firing the number of paintballs fired in each round etc the user has a choice of selecting one of these modes by activating the trigger 20 and or.