 SAAMI has set the pressure limit for this cartridge at 54,000 P.S.I.Its case length calls for a full-length magnum action, and surplus military actions chambered for the .308 Norma Magnum or the .300 Winchester Magnum offered a lower cost alternative for similar ballistics in the 1960s.The long .300 H&H case was designed for loading cordite, and those two modern magnum cartridges offered similar powder volume in a shorter case better adapted to ballistic uniformity with United States Improved Military Rifle (IMR) smokeless powder.