developed the Pedersen device attachment for the M1903 Springfield rifle that allowed it to fire a .30 caliber (7.62 mm) pistol-type cartridge in semi-automatic mode. This attachment was developed to allow an infantryman to convert "his rifle to a form of submachine gun or automatic rifle" in approximately 15 seconds. Production of the device and modified M1903 rifles started in 1918. However, the war ended before they were sent to Europe. The contract was cancelled on March 1, 1919, after production of 65,000 devices, 1.6 million magazines, 65 million cartridges and 101,775 modified Springfield rifles. The Pedersen device was declared surplus in 1931. To prevent them from falling into the hands of the lawless, nearly all of the stored devices were destroyed by the Army except for a few examples kept by Ordnance Department. In 1938, the U.S. Army Ordnance Department received a request for a light rifle to be issued to mortarmen, radiomen, drivers, clerks, cooks, and similar grades. During field exercises, these troops found that the M1 Garand rifle was too heavy and too cumbersome for general issue. And, while handguns are undeniably convenient, they had limited range, accuracy and power. This request was refused by authorities. In 1940, after Germany's use of glider-borne and paratroop forces to infiltrate and attack strategic points behind the front lines, the request for a light rifle was resubmitted and subsequently approved. U.S. Army Ordnance issued a requirement for a "light rifle" with greater range, firepower, and accuracy than the M1911 pistol while weighing half as much as the M1 Garand. As a result, the U.S. developed the semi-automatic M1 Carbine and shortly thereafter the select-fire M2 Carbine. Widely employed until the end of the Vietnam War, these carbines are generally considered the forerunners of modern personal defense weapons. Developed during the 1980s, the "Personal Defense Weapon" (PDW) concept was created in response to a NATO request as a replacement for 9×19mm Parabellum submachine guns. The PDW is a compact automatic weapon that can defeat enemy body armor and which can be used conveniently by non-combatant and support troops, as well as a close quarters battle weapon for special forces and counter-terrorist groups. Introduced in 1991, the FN P90 features a bullpup design with a futuristic appearance. It has a 50-round magazine housed horizontally above the barrel, an integrated reflex sight and fully ambidextrous controls. A simple blow-back automatic weapon, it was