Abstract: A safety air gun that discourages tampering with safety vent holes comprises an internal air channel for delivering pressurized air to a work area. The internal air channel has an expansion chamber of increased cross-sectional area, with an outlet nozzle being positioned at one end of the chamber and an inlet tube extending into the chamber from an opposite end of the chamber. The inlet tube and outer nozzle have ends that are closely spaced across a gap. The expansion chamber also has side vent holes that both relieve dead end pressure and admit ambient air into the pressurized air stream. The gap spacing and outlet contour are such that the air force from the outlet is lower when the vent holes are blocked than when the two vent holes are open.