8mm Remington Magnum (using Sierra bullets)
Date: Apr 22 2020
The 8mm Remington Magnum was formally introduced in 1977, based on the belted .300/.375 H&H Magnum case. The case was blown out with a 25-degree shoulder and necked to accept 8mm (.323-inch) bullets. Due to its 3.606-inch overall length, it requires a magnum length action. Remington was trying to further popularize metric designated cartridges bearing its name, such as the 6mm Remington Magnums and others. It was intended to provide a blend of flat-shooting characteristics and retained downrange energy without excess recoil, but it was also expected to fill the gap between the .300 Winchester Magnum, .300 Weatherby Magnum and the .338 Winchester and .340 Weatherby Magnums. Initially, factory loads included 185- and 220-grain bullets at 3,080 and 2,830 fps, respectively. Today the only surviving load from Remington contains the Swift 200-grain A-Frame bullet at 2,900 fps. Nosler also offers 180- and two 200-grain loads at 3,200 and 3,000 fps, respectively.
Unfortunately, 8mm cartridges have never sold particularly well in the U.S., and being sandwiched between other popular calibers, sales for the big 8mm were limited. Nonetheless, it is an excellent cartridge suitable for any game in North America as well as African plains game. With the recent introduction of the .325 Winchester Short Magnum (also an 8mm), there are many new premium hunting bullets that help make this cartridge better than ever.
The 8mm is relatively easy to develop handloads for, as it is well designed and did not build excess pressures unpredictably. Factory load performance was easily duplicated, and in several instance factory load velocities were exceeded using the Sierra 200-grain HPBT bullet and select powders. As with previous testing, best accuracy was usually obtained with loads that were maximum, or approaching maximum. A magnum primer is suggested to achieve reliable powder ignition under all circumstances and temperatures, with the Remington 9½ Magnum Primer, used herein.