The Navy plans to fire a high-speed, long-range rail-gun Hypervelocity Projectile from its deck-mounted 5-inch guns to destroy enemy drones, ships, incoming missiles and even submarines. Developed initially for an Electromagnetic Rail Gun next-generation weapon, The Hyper Velocity Projectile, or HVP, can travel at speeds up to 2,000 meters per second when fired from a Rail Gun, a speed which is about three times that of most existing weapons.
http://www.scout.com/military/warrior/story/1792092-navy-to-fire-rail-gun-round-from-5-inch-guns
