The .300 Ruger Compact Magnum or .300 RCM is a rimless, short-length rifle cartridge designed for the hunting of medium-to-large-sized North American game.
It is designed to closely duplicate the performance of the historic .300 Winchester Magnum cartridge, yet to be chambered in a short length action rifle.
Lighter bullets such as the 150 grain may offer a very flat trajectory up to considerable hunting distances, while heavier bullets such as the 180 and 200 grain may provide high ballistic coefficients, maintaining energy at long ranges and bucking wind more effectively.
The.300 Ruger Compact Magnum's greater case capacity, and the "short fat" cartridge efficiency lead to increases in the neighborhood of 150 fps over the H&H cartridge and is slightly slower than the .300 Winchester Magnum or .300 WSM.
As it may be chambered in short action light and compact rifles, the .300 Ruger Compact Magnum is a superb cartridge for the hunter who stalks game in difficult terrain where long shots are a common situation.