The Kynoch .500/.465 Nitro Express cartridge case is a specialized, high-caliber rifle cartridge developed by the British ammunition manufacturer Kynoch. Originally introduced in the early 20th century, it was designed specifically for use in big-game hunting rifles. The .500/.465 cartridge is notable for its impressive stopping power and reliability, making it an ideal choice for hunters targeting dangerous game, particularly in African safaris and other challenging environments.

With a case length of approximately 3.25 inches, this cartridge accommodates large amounts of gunpowder, delivering a high-velocity, hard-hitting round. The rimmed case design aids in smooth extraction and function in break-action and double rifles, which are typical platforms for this ammunition. The .500/.465 Nitro Express usually fires a 480-grain bullet at velocities up to 2,150 feet per second, delivering significant kinetic energy upon impact. This high energy level is essential for quickly immobilizing large, potentially aggressive animals. Known for its precision and quality, the Kynoch .500/.465 Nitro Express remains a respected choice among professional hunters and collectors, preserving a legacy tied to the history of classic British hunting cartridges