A paintball gun provides a double-acting trigger apparatus including a
pair of finger engagement surfaces against which a user of the gun may
employ a pair of trigger fingers. The user of the paintball gun may
effect a firing operation of the gun by using either one of the two
fingers to pull the trigger. Consequently, rapid firing operations of the
gun are effected by dithering the two trigger fingers in rapid
alternating motions to apply pressure on and off the two trigger
engagement surfaces. Further, the paintball gun includes a programmable,
microprocessor-based controller allowing the gun to be fired in response
to a chosen discreet event in time. This chosen discreet event may
include the opening and/or closing of a pair of switch contacts, for
example; or the making or breaking of an electrical circuit effected
between conductive components of the paintball gun. Movements of the
double-acting trigger apparatus will result in plural discreet events
separated in time, so that plural rapid-sequence firing operations of the
paintball gun may be accomplished. Accordingly, a very high cyclic rate
of fire is possible with a semi-automatic paint ball gun according to
this invention.