Initially a wildcat cartridge developed by Roy Weatherby in 1959 at the request of the United States Army. This white-hot cartridge is based on the 378 necked down to 30 caliber and packed with powder. Originally billed as the world’s fastest 30 caliber cartridge it will push a 30 caliber bullet 3500 feet per second. Reintroduced as a Weatherby production cartridge in 1996. - Caliber: 30-378 Weatherby Magnum - Bullet Type: Hammer Custom - Bullet Weight: 195 gr - Muzzle Energy: 4503 ft / lbs - Muzzle Velocity: 3225 fps - Rounds Per Box: 20