In order to simplify production, and to decrease the cost of ownership, the .50 AE was designed with a rebated rim which matched the diameter of the rim of the .44 Magnum, which was the most common caliber used in the Desert Eagle. By using the same rim dimensions as the .44 Magnum, a Desert Eagle could be converted from .44 Magnum to .50 AE by merely changing the barrel and magazine. Other convertible cartridges, such as the short-lived .41 Action Express (with the same rim diameter as 9×19mm Parabellum) used in the Jericho 941 convertible pistol and Uzi submachine gun and carbine, would function in the same magazine, and thus required only a barrel change to change caliber. The recent (early 2000s) Winchester Short Magnum, Winchester Super Short Magnum, and Remington Ultra Magnum and Remington Short Action Ultra Magnum families of rifle cartridges also feature rebated rims. All of these cases were based on the .404 Jeffery with the rim reduced from .543 inches to fit the .532 inch bolt face for existing magnum rifles. The .50 Beowulf uses a rebated rim design. This round is used in specialized AR-15 upper receivers, and the rim matches the size of the rim of the 7.62×39mm, allowing those parts to be used in the custom-built upper receivers. Rebated rims were also a feature of the cartridges of automatic cannons derived from the 20-mm Becker, of which the best known belong to the Oerlikon family. These "advanced primer ignition" (API) blowback weapons feature straight-sided chambers that are longer than necessary to contain the case. The face of the bolt has the same diameter as the case and follows it into the chamber. This means that the extraction claw also has to fit within the chamber, and therefore the case has a rebated rim. Another well known cartridge to use a rebated rim is the FN 5.7x28mm, used in the FN Five-seveN semi-automatic handgun and FN P90 personal defense weapon. The original purpose of the "belt" on belted cases (often referred to as belted magnums) was to provide headspacing; the extractor groove is cut into the belt just as it is cut into the case head on a rimless case. The belt acts as a rim on what is essentially a rimless case. The design originated in England around 1910 with the .400/375 Belted Nitro Express (also known as the .375/.400 Holland & Holland, and .375 Velopex).