The .41 AE Cartridge
While the .41 AE and the easy caliber conversion it provided was a good idea, the timing was just not right. The .41 AE used the same bullet diameter as the never very popular .41 Magnum, and since the .41 Magnum was primarily a revolver cartridge (though IWI did offer it in the Desert Eagle for a brief time) not all .41 Magnum bullets were suited to an autoloading design. The powerful 10 mm Auto cartridge, which had been suffering from poor acceptance from its start in the early 1980s, was eventually accepted by the FBI in a reduced power, subsonic loading. Smith & Wesson then decided that the 10 mm Auto was too much cartridge for the reduced power loading, and that the .45 ACP sized guns that chambered it were too heavy and bulky; out of this came the .40 S&W, a shortened 10 mm Auto case, designed to fit in a 9 mm sized gun, with a reduced pressure loading that allowed a lighter, easier to shoot gun. The near identical ballistics of the .40 S&W and the .41 AE are a result of convergent evolution in engineering; the .40 S&W starting from 10 mm Auto and moving to a shorter 9 mm length case and matching the ballistics of a reduced 10 mm Auto loading, and the .41 AE starting with a 9 mm and moving to the .41 caliber diameter to match a reduced .41 Magnum load.
In 1988, IWI also developed a 9 mm Action Express, which was a .41 AE necked down to 9 mm. It offered a much larger case capacity than the standard 9 mm case, allowing velocities that matched that of the .357 Magnum when loaded with light bullets. This move anticipated the parallel development of the .357 SIG from the .40 S&W in 1994.
While the .41 AE was doomed by circumstance to obscurity, the concept of using a rebated rim to allow easy cartridge interchangeability was not lost. The .50 Action Express, developed by IWI for the Desert Eagle pistol, uses a similar rebated rim that is the same diameter as the .44 Magnum. This allows a caliber change with replacement of just the barrel and magazine. Bottlenecked pistol cartridges, which also allow caliber changes with just a barrel change, have also started become available; Sturm Ruger made a limited edition convertible P Series pistol in 9 mm/.30 Luger, Sig Sauer released the .357 SIG, based on the .40 S&W, and Cor-Bon released the .400 Corbon based on the .45 ACP.
Read more about this topic: Jericho 941