Puff Lon Lubricating Filler, 500cc Use as a Gas Check, a Wad or Filler in Subsonic or Supersonic Ammunition Increases: Consistency, Accuracy, Barrel Life, and Reliability of Gas-Operated Automatics Decreases: Cleaning, Heating, Vibration, Fouling, Erosion, Gas Cutting, Friction, Extreme Spread Lubricates: The Barrel, the Projectile, gas-operated automatics and any part the gases reach. 500 cc  L = A volume equal to over 7,700 Grs. of gunpowder