The .50 Action Express (AE), also known as the 12.7×33mmRB, is a large-caliber handgun cartridge that gained fame for its use in the Desert Eagle pistol. Here are some key details about this powerful cartridge:

1. Origin and Development:
   • The .50 AE was designed in 1988 by Evan Whildin of Action Arms in the United States.
   • It was specifically intended for use in the Desert Eagle pistol, manufactured by Israeli Military Industries (IMI) and Magnum Research¹.
2. Cartridge Specifications:
   • Bullet Diameter: The actual bullet diameter is 0.500 inches (12.7 mm).
   • Case Type: Rebated and straight.
   • Base Diameter: 0.543 inches (13.8 mm).
   • Rim Diameter: Same as the .44 Remington Magnum cartridge.
   • Maximum Pressure: 36,000 psi (250 MPa).
   • Ballistic Performance: Factory loads can produce nearly 1,800 ft⋅lbf (2,400 J) of muzzle energy¹.
3. Polygonal Rifling and Legal Challenges:
   • Initially, the .50 AE had a bore diameter of 0.500 inches with conventional rifling.
   • However, the switch to polygonal rifling caused the gauge plug to drop through, making the gun a destructive device under Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) regulations.
   • The actual bullet diameter was then reduced to the current 0.500 inches (12.7 mm) to comply with regulations¹.
4. Recoil and Other Firearms:
   • Recoil of the .50 AE in the Desert Eagle pistol is substantial but only marginally more severe than the .44 Magnum.
   • Other firearms chambered for the .50 AE include the AMT AutoMag V, LAR Grizzly Win Mag, Magnum Research BFR, and the Freedom Arms Model 555¹.