Definitions for ".375 Remington Ultra Magnum"
The .375 Remington Ultra Magnum is a .375 rifle cartridge introduced by Remington Arms in 2002. It is a beltless, rebated rim cartridge based on the .404 Jeffery. It is at the top of the heap as far as .375 cartridges go, outshined only by the massive .378 Weatherby.