Abstract: A gas propelled munitions anti-fouling system has a case having an open forward mouth end, a rear end, and an interior, the rear end defining a pocket that receives a primer and a passage communicating between the pocket and the interior of the case, a quantity of propellant received within the interior of the case, a quantity of anti-fouling composition received within the interior of the case, and a bullet having a rear portion inserted into the open forward mouth end of the case. The anti-fouling composition may have at least one salt and at least one acid. The acid may be anhydrous. The salt may be sodium chloride or sodium nitrate. The acid may be anhydrous citric acid. The anti-fouling composition may have at least one abrasive. The abrasive may be stannic acid. The anti-fouling composition may be 50% salt by weight and 50% acid by weight.