Bismarck.Dracondria said:
»Fun Fact: The Desert Eagle comes in .357 Magnum, .44 Magnum, and .50 Action Express. The .50 AE cartridge, while having a larger projectile, has a rebated rim which is the same diameter as the rim on a .44 Mag cartridge. A .50 AE model can be converted to .44 Magnum by swapping the barrel and magazine, a very easy process.
Desert Eagles are also gas operated and because of this, use of cast lead projectiles (bullets) will lead to malfunction due to lead dust in the gas tube.
EDIT: That's a .50 AE pictured, I dunno what the phone is.