|.458×2 inch American|
|Place of origin||USA|
|Parent case||.458 Winchester Magnum|
|Case type||Straight belted|
|Bullet diameter||.458 in (11.6 mm)|
|Neck diameter||.481 in (12.2 mm)|
|Base diameter||.513 in (13.0 mm)|
|Rim diameter||.532 in (13.5 mm)|
|Rim thickness||.050 in (1.3 mm)|
|Case length||2.000 in (50.8 mm)|
|Case capacity||73 gr H2O (4.7 cm3)|
The .458×2-inch American was designed as a medium power big bore cartridge by Frank Barnes for North American big game. Frank Barnes found that the .458 Winchester Magnum and the .460 Weatherby Magnum too powerful for North American big game and believed that a cartridge of lesser power would be ample for the task.
The cartridge has the power required to take all North American big game species. It is also adequate for African dangerous game in close cover.
The .450 Marlin and the .458×2-inch American are very similar cartridges. The cartridges are essentially the same length. However, the .450 Marlin will not chamber in the .458×2-inch American as the belt on the .450 Marlin is considerably wider. The .458×2-inch American should not be fired in a .450 Marlin as failures may occur. While not interchangeable, the .458×2-inch American will do anything the .450 Marlin is capable of accomplishing, and converting such a rifle to .450 Marlin is fairly straightforward.
The .458×2-inch American was intended for bolt action rifles. The first rifle chambered for the cartridge was a Remington Model 722. The cartridge also can be chambered for the Winchester Model 94 lever action rifle.