The 375 Remington Ultra Magnum which is abbreviated as the 375 RUM, is a rifle cartridge developed by Remington Arms in 2002. It's a beltless, rebated rim cartridge that's made by necking up a.300 Remington Ultra Magnum case to.375 caliber with no additional modifications. The 338 features a slightly shorter case than the 338 RUM in order to maintain a comfortable cartridge overall length (COAL) inside the confines of the Remington M700 rifle magazine.
The.375 RUM has had little popularity since its inception. Nonetheless, the.375 RUM is a powerful cartridge, capable of pushing a 300 grain (19 g) bullet at 2760 ft/s (840 m/s), producing 5070 ft·lbf (6.88 kJ) of energy. This bullet's muzzle velocity may be increased to a maximum of 2950 ft/s (900 m/s) by handloading, producing 5800 ft lbf (7.9 kJ).
Large, thick-skinned game should be the primary target for the 375 Remington Ultra Magnum. It has the power to kill any land mammal and can do it over a great distance because of its rapid velocity. However, such performance comes at the cost of a high recoil: this cartridge can create a ferocious 80 ft lb (108 J) of recoil in a sporting-weight rifle weighing 8 lb (3.6 kg) (approximately 3.5 times that of a .30-06.) Most shooters' capabilities go well above this. There is a good assortment of.375 in (9.53 mm) bullets that are suitable to the.375 RUM's high velocity, and boat tail rounds assist to increase the usable range even more.
