The 300 Weatherby Magnum was wildcatted by Roy Weatherby in 1944 and was among his initial cartridges when he went into production in 1945. The 300 Weatherby Magnum remains the flagship of the Weatherby line, the most popular of the Weatherby Magnums. It is based on the 300 H&H case blown out, retaining the full (2.85-inch) case length and adding Weatherby's distinctive "double Venturi" shoulder. It is thus just one of numerous "improved" versions of the 300 H&H, but easily the most popular and the only one readily available in factory form. The 300 Weatherby Magnum is fast, flat-shooting, and powerful, and has been the choice of many serious globe-trotting hunters since its inception. Factory loads are available from Federal, Hornady, and Remington as well as Weatherby. Weatherby factory loads include: 150-grain bullet at 3540 feet per second; 165-grain bullet at 3390; and 180-grain bullet at 3240.
