thumb|The [[FN P90, one of the most well-known personal defense weapons (PDW)]]
Personal defense weapons (PDWs) are compact magazine-fed automatic firearms, typically performing as a submachine gun designed for secondary defensive use rather than as a primary service weapon. Some PDWs fire a small-caliber (generally less than in bullet diameter), high-velocity centerfire bottleneck cartridge resembling a scaled-down intermediate cartridge, essentially making them an "in-between" hybrid between a submachine gun and a conventional carbine assault rifle.
The name describes the weapon's original conceptual role: as a compact but powerful small arm that can be conveniently carried for personal defense, usually by support personnel behind the front line such as military engineers, logistic drivers, medical specialists, artillery crews, or signallers. These "second-line" personnel are not strictly combat troops expected to directly engage the enemy, but may still be at risk of encountering decently equipped (and often well-armored) hostile skirmishers and infiltrators, therefore having to defend themselves in close quarters. Such encounters were thought to warrant an effective weapon that would have sufficient range for engagements that exceed handgun capabilities, but without the unnecessary bulk of a full-sized service rifle causing a burden during their normal duties. However, the concept has generally proven unsuccessful for this application, with carbines still being widely preferred for these roles.
History
thumb|9mm Parabellum "Red 9" Mauser C96 with stock
In the late 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 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.
thumb|Pedersen device drawing
During World War I, the United States secretly developed the Pedersen device attachment for the M1903 Springfield rifle that allowed it to fire the .30-18 Auto (7.65×20mm Longue) pistol 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. The Pedersen device was declared surplus in 1931. 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. the request for a light rifle was resubmitted and subsequently approved. As a result, the U.S. developed the semi-automatic M1 Carbine and shortly thereafter the select-fire M2 Carbine.
right|thumb|[[AO-46 (firearm)|AO-46]]
In 1969, AO-46 was an unsolicited design by Peter Andreevich Tkachev working at TsNIITochMash. Although not accepted for service, this design, in combination with report of the US use of the XM-177 in Vietnam led the GRAU to start the competition known as Project Modern, which led to the adoption of AKS-74U for service.
right|thumb|[[Heckler & Koch MP7A1]]
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. 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
thumb|Three civilian [[5.7×28mm cartridges as used in the P90. The left cartridge has a plain hollow tip, the center cartridge has a red plastic V-max tip intended to ensure bullet expansion, and the right cartridge has a blue plastic V-max tip.]]The PDW concept has not been widely successful, partly because existing PDWs are not significantly cheaper to manufacture than carbines or full-size military rifles. Most PDWs also use a proprietary cartridge, such as the 5.7×28mm cartridge for the FN P90 or the 4.6×30mm for the H&K MP7, neither of which were originally compatible with any existing pistols or rifles/carbines. Although both manufacturers planned handguns that used the same proprietary rounds, only FN went forward with production of the Five-SeveN pistol, which was the only handgun option available for the 5.7×28mm cartridge for over two decades until the introduction of Ruger-5.7 in 2019. In turn, this made the PDW cartridges expensive to consumers due to the lack of mass production.
Though personal defense weapons have not been very popular for their intended application, they have been acquired by various military special forces units and law enforcement groups, as an upgrade for their older submachine guns. The FN P90 and Five-seven pistol are used by military and police forces in over 40 countries, 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.
PDW cartridges
- 4.38×30mm Libra
- HK 4.6×30mm
- .224 Boz
- FN 5.7×28mm
- 5.8×21mm DAP
- 6.5×25mm CBJ
- 7.92×24mm
- 9×21mm Gyurza
Traditional personal defense weapons
{| class="wikitable sortable"
|+
!Name
!Cartridge
!Country
!Serial production
|-
|Brügger & Thomet APC9 RWS ACTION SE Gen. II SXF variant
|9×19mm, regular loads and armor piercing RWS ACTION SE Gen. II SXF loads
|Switzerland
|
|-
|Brügger & Thomet MP9
|6.5×25mm CBJ, 9×19mm
|Switzerland
|yes
|-
|Colt SCAMP
|.22 SCAMP
|United States
|no
|-
|ČZW-438
|4.38×30mm Libra
|Czech Republic
|no
|-
|FN P90
|5.7×28mm
|Belgium
|yes
|-
|Heckler & Koch MP7
|4.6×30mm
|Germany
|yes
|-
|Saab Bofors Dynamics CBJ-MS
|6.5×25mm CBJ
|Sweden
|no
|-
|SR-2 Veresk
|9×21mm Gyurza
|Russia
|yes
|-
|ST Kinetics CPW
|4.6×30mm, 5.7×28mm, 9×19mm
|Singapore
|yes
|-
|Tuma MTE 224 VA
|.224 Voboril
|Switzerland
|no
|-
|VBR-Belgium PDW
|9×19mm Parabellum
|Hungary
|yes
|
|-
|Heckler & Koch MP5K-PDW
|9×19mm Parabellum
|Germany
|yes
|
|-
|Knight's Armament Company PDW
|6×35mm KAC,.300 Blackout
|United States
|yes
|
|-
|Magpul PDR
|5.56×45mm
|United States
|no
|
|-
|SAI SMG Tiger Cub
|9×19mm Parabellum
|Denmark
|yes
|
|-
|SIG MCX Rattler
|5.56×45mm, .300 Blackout
|United States
|yes
|
|}
See also
- Assault rifle
- Assault weapon
- Machine pistol