This authentic, once fired 50-caliber machine gun cartridge on your desk makes for a great conversation piece. Pull out the solid copper bullet and flip it for a unique and convenient writing instrument. The 50-caliber shell acts as a holder and stand for the easily removable pen inside. The closed cartridge measures 5.5 inches and the bullet pen measures 5 inches long. Hardwoods such as cherry, oak, maple or walnut are used for the pen body. The pen includes a Parker style ink cartridge, which is available at most office supply stores or on line..