he Fisher Space Pen .338 Caliber Cartridge Ballpoint Pen is made from a genuine .338 caliber LAPUA Mag brass casing and a finish of lacquered and raw brass. Because the cap on the Fisher Space Pen .338 Cartridge Ballpoint Pen is made from an actual .338 Mag shell there is no finish on that portion of the pen. Over time it will color and create its own unique look. It is also not recommend to take this pen on an airplane as TSA may believe it to be a real bullet.