A spray gun includes a valve cartridge configured to be axially installed and removed as a single piece. The valve cartridge includes the wear components of the spray gun. A trigger of the spray gun is configured to actuate a slider of the valve cartridge to control spraying by the spray gun. The trigger includes arms that are mounted to the spray gun by a pivot mechanism. The pivot mechanism can be disengaged from the arms to allow the trigger to slide between a spray position, where the trigger prevents forward axial movement of the valve cartridge, and a repair position, where the valve cartridge can move axially forward. The trigger also includes upper and lower portions that are movable relative to each other, such that the length of the trigger can be adjusted.