The .264 Winchester Magnum is a belted, bottlenecked rifle cartridge. Except for the .244 H&H Magnum and .257 Weatherby Magnum, it is the smallest caliber factory cartridge derived from the Holland & Holland belted magnum case. It was introduced in the late 1950s and early 1960s with the .338 Winchester Magnum and the .458 Winchester Magnum as one of a family of short-cased belted magnum cartridges developed by Winchester based on the .375 Holland & Holland parent case. It was officially introduced to the public by Winchester in 1959. After many years of dwindling use it began enjoying a mild resurgence in popularity in the mid-2000s among long range rifle enthusiasts and reloaders due to the high ballistic coefficient of the heavier 6.5mm bullets and increasing popularity of cartridges such as 6.5mm Creedmoor, .260 Remington, 6.5 Grendel, benchrest and wildcat cartridges in 6.5mm. Design & specifications Winchester had been manufacturing the shortened Holland & Holland cases under a contract for Weatherby for use in their .257 Weatherby Magnum, .270 Weatherby Magnum and 7mm Weatherby Magnum cartridges. The Weatherby cases had been based on Winchester's .30 Super cartridge. This new series of shortened Holland & Holland cases was based on the .375 Holland & Holland case. The advantages of the shortened case were twofold: the cartridge could function through the standard length rifle action as used by the popular .30-06 Springfield and .270 Winchester. It was also close to the efficiency limitations of powders available at the time given the case capacity of the cartridge. The longer, full length .375 H&H case would not have resulted in a great performance improvement due to the powders available at that time. It was similar to the reasoning behind the shortened cases used by Weatherby as DuPont's IMR 4350 was the slowest burning powder available then. The .264 Winchester Magnum is a cartridge which was standardized by SAAMI, which published recommended specifications for the cartridge. SAAMI recommends a six groove barrel with a rate of twist of one revolution in , a bore diameter of and a groove diameter of with each groove having a width of . The recommended maximum pressure for the cartridge (piezo) is . Performance The .264 Winchester Magnum gained a reputation as a very flat shooting cartridge. When introduced, it was first chambered in the Winchester Model 70 Westerner rifle, which was intended for longer range shooting more common