The .300 Norma Magnum was developed by Sweden's Norma in 2012 and must not be confused with the older belted-case .308 Norma Magnum. The .300 Nor Mag and its predecessor, the .338 Nor Mag are based on the large-diameter .416 Rigby case, which is also the parent case for the .338 Lapua Magnum. The .300 Nor Mag uses this big case shortened to 2.492 inches, thus taking the short fat unbelted case design to new levels. While the .300 Norma Magnum's case length allows it to be housed in a .30-06-length action, the very large .588-inch rim and .585-inch base diameter need an extra-large bolt face that cannot be accommodated by many sporting actions. Like all "fast .30s" the .300 Norma Magnum would be a versatile and useful hunting cartridge, but it was designed primarily for accuracy and long-range performance; many countries with military sniping programs have considered it and in 2016 US Special Operations Command (SOCOM) adopted the .300 Norma Mag as their Advanced Sniper Rifle Cartridge
