.50 Action Express

The .50 Action Express (AE) (12.7×33mmRB) is a large-caliber handgun cartridge, best known for its usage in the Desert Eagle. Developed in 1988 by American Evan Whildin of Action Arms, the .50 AE is one of the most powerful pistol cartridges in production.

Overview
The actual cartridge has a .543 in base, with a rebated rim. The rim diameter of the .50 AE is the same as the .44 Remington Magnum cartridge. A Mark XIX Desert Eagle in .50 AE can be converted to .44 with nothing more than a barrel and magazine change.

The introduction of the .50 AE in the United States was met with a rocky start. Federal firearms statutes state that non-sporting firearms may not be over 0.500 inches in bore diameter (measured land to land) to meet Title I regulations. The original .50 AE bore diameter was .500 in, with conventional rifling, but the switch to polygonal rifling on production Desert Eagles allowed the gauge plug to drop through, rendering the gun a destructive device under Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) regulations. Actual bullet diameter was reduced to the current 0.500 in rather than the original 0.510 in – thus the noticeably tapered case.

Recoil of the .50 AE in the Desert Eagle pistol is substantial, although only marginally more severe than the .44 Magnum, as the automatic mechanism and weight of the gun smooth the recoil somewhat. Other firearms chambered for the .50 AE include the AMT AutoMag V, the LAR Grizzly Win Mag, the Magnum Research BFR, and the Freedoms Arms Model 555.

Performance
SAAMI specifies a maximum chamber pressure of 36,000 psi for the .50 AE. Available factory loads can produce nearly 1,800 ftlbf of muzzle energy.

Use
Like other handgun cartridges of such magnitude, the principal uses of the .50 AE are metallic silhouette shooting and medium/big game hunting. Like the .44 Magnum, .454 Casull, .460 S&W Magnum, and .500 S&W Magnum, it is also well suited for defense against large predators, such as bears. With heavier bullets, such as the TII Armory 400-grain and 460-grain offerings, the .50 AE closely matches the performance of the .480 Ruger and approaches the ballistics of the .500 Linebaugh.

The .50 AE as a parent case
The .50 AE is the parent case for the .440 Cor-Bon (1998) by Cor-Bon and the .429 DE (2018) by Magnum Research (a division of Kahr Firearms Group). Though similar, they are not interchangeable. Desert Eagle magazines for .50 AE cartridges can feed the derivative cartridges, but should be paired with barrels appropriate for their cartridge and caliber.