Go big, or stay home. A 45 pound projectile is 315,000 grains. That should do the trick.
http://www.foxnews.com/tech/2015/04/15/navy-will-test-its-electromagnetic-railgun-aboard-ddg-1000/?intcmp=ob_article_footer_text&intcmp=obinsiteThe railgun uses electrical energy to create a magnetic field and propel a kinetic energy projectile at Mach 7.5 toward a wide range of targets, such as enemy vehicles, or cruise and ballistic missiles.
"The weapon works when electrical power charges up a pulse-forming network. That pulse-forming network is made up of capacitors able to release very large amounts of energy in a very short period of time. The weapon releases a current on the order of 3 to 5 million amps --- that's 1,200 volts released in a ten millisecond timeframe. That is enough to accelerate a mass of approximately 45 pounds from zero to five thousand miles per hour in one one-hundredth of a second," Ziv added.
The hypervelocity projectile is a kinetic energy warhead, meaning it has no explosives engineered into it. This lowers the cost and the logistics burden of the weapon, Ziv said.
The rate of fire is 10-rounds per minute, Ziv said.
Due to its ability to reach speeds of up to 5,600 miles per hour, the hypervelocity projectile is engineered as a kinetic energy warhead, meaning no explosives are necessary. The hyper velocity projectile can travel at speeds up to 2,000 meters per second, a speed which is about three times that of most existing weapons
