Abstract: A dispensing apparatus, such as a caulking gun, includes an elongated handle having a U-shape cross section to define an internal space. A support member is mounted on the handle configured for receiving a dispensing cartridge having a nozzle at one end and being sealed at the other end by a slidable diaphragm or seal. A plunger rod and piston assembly is mounted on the handle for operatively engaging the cartridge diaphragm to dispense compounds or viscous mediums from the open nozzle of the cartridge. A trigger is pivotally attached to the handle for incrementally advancing the plunger assembly as the trigger is pulled from an extended position most remote from the handle to a retract position most proximate to the handle. A spring normally urges the trigger to move to the extended position. An aperture is provided in the handle for receiving at least a portion of a nozzle of a dispensing cartridge.