|Place of origin United States|
|Designer Hornady and Marlin Firearms|
The .450 Marlin is a firearms cartridge designed as a modernized equivalent to the venerable .45-70 lever-action cartridge. It was designed by a joint team of Marlin and Hornady engineers headed by Hornady's Mitch Mittelstaedt, and was released in 2000, with cartridges manufactured by Hornady and rifles manufactured by Marlin, mainly the Model 1895M levergun. The Browning BLR is also now available in .450 Marlin chambering. Marlin ceased manufacture of the 1895M rifle in 2009. It is not known if or when this model will be available again.
While ballistically similar to the .45-70, the .450 Marlin was not developed from the .45-70. Rather, the .450 Marlin was developed from the wildcat .458×2" American, which was based on the .458 Winchester Magnum. This places the .450 Marlin in the .458 Winchester family of cartridges, though it is more easily understood as a "modernized" .45-70.
The belt has been modified to prevent it from chambering in smaller-bore 7mm Magnum or .338 Magnum rifles. The .45-70 and .450 Marlin cannot be cross-chambered, but rifles chambered for the .458x2 can be modified to fire the .450 Marlin.
Visually, the case resembles that of the .458 Winchester Magnum with a wider belt. The cartridge is most useful for hunting big game at short ranges, being accurate at ranges of 150 to 175 yards (137 to 160 m). The cartridge is capable of taking any large game animal in North America including large elk, brown bear and moose.