A pepper spray gun assembly having a trigger valve for dispensing a non-lethal spray, such as a pepper spray. The assembly includes a storage cylinder for receiving a non-lethal spray charge and a smaller pre-charged charging cylinder for engaging the storage cylinder. The charging cylinder is fluidly coupled to the storage cylinder so as to provide a regulated gas in the head space of the storage cylinder. When the trigger of the trigger valve is operated, the regulated gas will force the charge to be expelled through the nozzle of the trigger valve assembly.
