Abstract: A method and apparatus for making gas flushed packages in a vacuum chamber machine which includes a bag mouth clamp spaced apart form seal bars disposed to transversely seal the bag neck. A vertically moveable piercing blade and nozzle penetrate the upper wall of the bag neck as the chamber pressure is lowered and the bag "balloons" thereby causing the upper and lower neck walls to separate. Once the bag is pierced and the residual air escapes, a predetermined amount of gas is injected and then the bag is sealed. If desired, sufficient gas can be injected to make a pillow pack.