This is .300 Weatherby Magnum 165gr. Nosler Ballistic Tip Ammo. The .300 Weatherby Magnum had the flattest trajectory, longest range and the greatest killing power of any .300 magnum on the market until the .30-378 Weatherby Magnum came along. Based on the .300 H&H Magnum, the .300 Weatherby delivers 300 more fps than its British cousin. Introduced in 1944, this is the all-around cartridge for the big game hunter. Weatherby uses only the finest components, such as Norma brass, to assure that each load is as precise as a shooter's favorite handload. Premium ammunition for premium performance. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases. This ammo comes packed in 20rd. boxes.