Personal defense weapon


Personal defense weapons are a class of compact, selective fire, magazine-fed, submachine gun-like firearms—essentially a hybrid between a conventional submachine gun and a military-style rifle. Most PDWs fire a small-caliber, high-velocity centerfire bottleneck cartridge resembling a scaled-down intermediate rifle cartridge. This gives the PDWs better effective range, accuracy and armor-penetrating capability than submachine guns, which fire larger-caliber but slower and less aerodynamic handgun cartridges.
The name describes the weapon's original conceptual role: as a compact but powerful small arm that can be conveniently carried by support troops behind the frontline such as military engineers, logistic drivers, artillery crews or signallers. This person may be at risk of encountering decently equipped enemy infiltrators and having to defend themselves in close quarters, which warrants an effective weapon that can suppress enemy charges and hold them beyond a safe distance to prevent the defenders from being overrun, but such risk is rare enough that a long-barrel service rifle would be an unnecessary burden during their normal duties. Because of their ease of use, lightweight, and controllability, PDWs have also been used by special forces, paramilitaries, heavily-armed police and even bodyguards.

History

In the 19th and early 20th centuries, shortened versions of the infantry rifle were issued as "carbines" for cavalry troops and gun crews. This designation was dropped as infantry rifle designs became shortened overall, such as in the Short Magazine Lee–Enfield rifle. Thereafter, handguns were typically issued as a self-defense weapons. However, they were not effective in most close combat situations. As a result, during the First World War, the Mauser C96 and artillery versions of the Luger pistol were issued with attachable shoulder stock holsters, which allowed for greater control and accuracy.
During World War I, the United States secretly developed the Pedersen device attachment for the M1903 Springfield rifle that allowed it to fire a.30 caliber 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 during 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 late 1980s, the "Personal Defense Weapon" 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 designed to fire the FN 5.7×28mm cartridge which can penetrate soft body armor. The P90 was designed to have a length no greater than a man's shoulder width, to allow it to be easily carried and maneuvered in tight spaces, such as the inside of an armored vehicle.
Introduced in 2001, the Heckler & Koch MP7 is a direct rival to the FN P90. Featuring a more conventional-looking design, the MP7 uses a short-stroke piston gas system as used on H&K's G36 and HK416 assault rifles, in place of a blowback system traditionally seen on submachine guns. The MP7 is able to use 20-, 30- and 40-round magazines and fires 4.6×30mm ammunition which can penetrate soft body armor. Due to the heavy use of polymers in its construction, the MP7 is much lighter than older SMG designs, weighing only with an empty 20 round magazine.

Applications

The PDW concept has not been widely successful, partly because PDWs are not significantly cheaper to manufacture than full-size military rifles. PDWs use a proprietary cartridge, such as the 5.7×28mm cartridge for the FN P90 or 4.6×30mm for the Heckler & Koch MP7, neither of which were originally compatible with any existing pistols or rifles. A different take on the PDW concept is the Russian made PP-2000, which can fire common 9×19mm Parabellum ammunition or a special high-pressure armor-piercing version to give it similar capabilities as other PDWs.
Though personal defense weapons have not been very popular for their intended application, they have been acquired by many special forces and law enforcement groups as direct replacements for submachine guns. The FN P90 and Five-seven pistol are used by military and police forces in over 40 countries throughout the world, including Canada, Cyprus, France, Greece, India, Peru, Poland, Spain, and the United States. The Heckler & Koch MP7 is also used in a number of countries, including Austria, France, Germany, Ireland, Norway, Malaysia, and the United Kingdom.

Modern personal defense weapons