420 mm artillery

The term "420 mm artillery" typically refers to large-caliber artillery pieces that fire projectiles with a diameter of 420 millimeters (approximately 16.5 inches). This caliber is notably associated with heavy artillery systems that are designed for long-range bombardment and can cause significant destruction. One of the most well-known examples of a 420 mm artillery piece is the German "Dora" and "Großdeutschland" railway guns used during World War II.