ABOVE: A crude Chinese made copy of the Mauser C96 pistol with detachable buttstock.
During World War I, the primary weapon issued was the full-power, long range battle rifle, while many officers were issued revolvers or pistols as a personal defense weapon. Handguns, which with their limited range, are generally considered a “last ditch” defensive weapon. The advantage was their relatively small size, which did not interfere with a soldier’s routine non-combat duties.
In the past, efforts were made to increase the effectiveness of hand guns by adding a detachable buttstock and a full-auto capability. Select-fire pistols with detachable stocks were produced by Mauser, Star and others, and they were very popular during the warlord era in China. Although the concept had been long considered obsolete, machine pistols reemerged, based on modern pistol designs like the Soviet APS Stechkin, the Beretta 93R, the Glock 18 and others. Similar weapons were based on existing submachine guns. Heckler and Koch began the trend in 1976 with the MP5K, a small stockless version, of their MP5 submachine gun. Israeli Military Industries introduced their compact 9mm Mini UZI in 1980 and the Micro Model in 1986, both weapons were based on the standard size UZI submachine gun.
The U.S. M1 Carbine
Recognizing the limitations of the pistol as an effective combat weapon, the U.S. proposed the light rifle concept in 1938. The idea was to provide a lightweight, compact personal weapon to arm support troops not directly involved in combat. The “light rifle” was adopted as the M1 carbine in 1941. The carbine weighs only 5.8 pounds with a loaded 15-round detachable magazine, and has an overall length of 35.6 inches. During the last months of World War II a select-fire version of the carbine, the M2, and accompanying 30-round magazine, was introduced. The carbine fired a relatively small 7.62x33mm cartridge with a 110 grain FMJ bullet at a velocity of approximately 1970 feet per second. Recoil was mild compared to the primary U.S. battle rifle, the 30’06 caliber (7.62x63mm) M1 Garand.
During World War II the submachine gun, firing pistol caliber cartridges, came into widespread use. The United States and many allied nations adopted the Thompson submachine gun. The Thompson was expensive, heavy and a somewhat cumbersome weapon, whose design was nearly twenty years old in 1941. As the war went on many new more modern designs emerged, which were smaller, lighter and cheaper to manufacture. During the period following World War II more compact submachine gun/machine pistol designs were introduced, like the Military Armament Corporation’s MAC 10 and MAC 11, which were only slightly larger in size than many handguns.
As World War II went on, yet another class of small arms was introduced by the Germans, the Sturmgewehr. The revolutionary weapon fired an intermediate range cartridge, in between the long-range battle rifle and the short range submachine gun. The Sturmgewehr had acceptable range capability and was controllable when fired in its full-automatic mode. The assault rifle was born and it would change the way armies viewed infantry small arms.
During the post-World War II years the Soviets, following the midrange infantry rifle concept of the German Sturmgewehr, introduced their soon to be infamous AK-47 rifle. Now there were a number of categories of small arms: the pistol, the machine pistol, the submachine gun, the assault rifle and the battle rifle. The assault rifle replaced many of the aforementioned weapons in most modern armies. During 1959, the United States adopted the short-lived 7.62x51mm M14 rifle, which was replaced by the small caliber high-velocity 5.56x45mm M16 rifle in 1964. During 1976, the Soviets adopted the AK-74 firing the small caliber high-velocity 5.45x39mm round. Before long, compact models of the AK-74 and M16 were designed and adopted as the AKS-74U
and CAR-15 respectively.
Return of the Submachine Gun
After the introduction of the midrange assault rifle, the submachine gun was considered obsolete as a military weapon. However, the proliferation of increasing violent, and well-armed, drug gangs operating in the U.S. during 1970 thru the 1980s forced many law enforcement agencies to adopt automatic weapons so they wouldn’t be outgunned by their criminal adversaries. One of the most popular weapons was the submachine gun, which with its short range was an asset to minimize collateral damage. The weapon of choice for many law enforcement agencies was Heckler and Koch MP5 made in Germany. The MP5 is a compact, select-fire 9mm weapon that is accurate in semiautomatic and quite manageable in full automatic. The MP5 was able to accommodate a sound suppressor, which when used with subsonic 9mm ammunition provided stealth when needed. Eager to get in on the growing worldwide law enforcement submachine gun market, Colt introduced a 9mm version of their M16 rifle in 1980. One of Colt’s selling points was operation and training for the Colt 9mm SMG is similar to that for the M16, substantially simplifying the familiarization process, and that the weapon was U.S. made, an important considerations for many agencies during the period.
More recently, many law enforcement agencies have begun to replace their submachine guns with the more powerful 5.56mm M4 carbines and the compact Colt Commando. The reason was to match the firepower of their criminal and terrorist adversaries, who often are armed with AK-47 type weapons, as well as their increasing use of personal body armor.
Modern Personal Defense Weapons
The development of the modern PDW began with a 1989 NATO request for a new personal defense weapon to replace current 9mm NATO caliber submachine guns. What was being sought was something more effective than a submachine gun, but less powerful than an assault rifle. Submachine guns were proving ineffective in the face of new threats and the emergence of new ballistic protections. Assault rifles, like the 5.56mm M4 were considered too powerful for lethal engagements in densely populated areas. The NATO request for a more effective weapons resulted in a widespread development of new
cartridges and firearms.
Designers have redefined the Personal Defense Weapon or PDW. Some of the weapons are completely new designs, while others are hybrids of existing weapons. A modern personal defense weapon is now defined as one that is compact, easily concealed, fitted with modern optics. Most modern PDWs fire a small, but powerful bottle-neck cartridge. A PDW is desirable in a high threat situation were a pistol or submachine gun would normally be carried. The concept was introduced during the late 1980s primarily because of the increasing widespread use of modern body armor, which weapons firing the NATO 9mm round cannot not penetrate.
One of the earliest weapons in the new personal defense class to reach series production during 1990 was the FN P90. The weapon was developed by the Belgian firm of FN Herstal. The FN P90 fires a small high-velocity 5.7×28mm caliber bottle-neck, centerfire round also developed by FN. The original cartridge was called the SS90, featuring a 23 grain plastic-core projectile, which had a muzzle velocity of approximately 2,800 feet per second when fired from the P90 weapon. The cartridge has been updated since its introduction. The FN P90 feeds from a unique top-mounted 50-round magazine. The P90 is a selective fire, blowback-operated weapon with a cyclic rate of 900 rounds per minute. The ambidextrous P90 fires from a closed bolt for maximum accuracy, and its design makes extensive use of polymers for reduced weight and cost. Overall, the weapon is relatively lightweight, weighing 6.6 pounds (3kg) with a loaded 50-round magazine. FN also offers a semiautomatic pistol, the FN FiveseveN, that fires the same 5.7x28mm cartridge as the FN P90.
Heckler and Koch introduced their MP7 Personal Defense Weapon in 2001 chambered for their proprietary 4.6×30mm cartridge. A new cartridge designed to meet NATO requirements published in 1989, as these requirements call for a personal defense weapon (PDW) class firearm, with a greater ability to defeat body armor than current weapons limited to conventional pistol cartridges. The 4.6x30mm proprietary cartridge was developed jointly by HK and Royal Ordnance (RO), HK’s parent company and a division of BAE Systems. The standard full metal jacket bottleneck cartridge has a 2.7 g bullet with an alloy core and a steel copper plated jacket. Muzzle velocity is approximately 2,000 feet per second (600 m/s). There are also special loadings available that include the Law Enforcement Hollow Point, and the DM11 Penetrator Ultimate Combat round.
The MP7 is gas operated using a short stroke piston and rotating bolt. Barrel length is 7.1-inches (180mm). The weapon is fed from a detachable box magazine available in 20, 30 and 40 round capacities. The full auto cyclic rate is 950 rounds per minute. The weapon weighs 2.76 pounds (1.25kg) with magazine; overall length with the stock extended is 25.1-inches (638mm) with the stock folded the length is reduced to 16.3-inches (415mm). Since introduced, the MP7 has been updated. The current production versions are the MP7A1 and the MP7A2.
There were other attempts at developing a personal defense weapon, however, few have progressed past the experimental stage.
Colt attempted to enter the PDW market during the 1990s with their Mini Assault Rifle System or MARS. The prototype weapon was based on the proven M16 rifle, chambered for an experimental 5.56×30mm MARS cartridge. The MARS cartridge fired a 55-grain projectile at a velocity of 2,592 feet per second (790 m/s).
ST Kinetics of Singapore developed a multi-caliber, delayed blow-back submachine gun designated as a Compact Personal Weapon or CPW. The loaded weight of the CPW with a 30-round magazine is only 4.4 pounds (2.0kg). The weapon is select-fire, with a full-auto cyclic rate of fire of 900 to 1100 rounds per minute. Barrel length is 7-inches (180mm) with an open prong flash hider, overall length is 13.78-inches (350mm). Although the original prototype was chambered in 9×19mm, the weapon was designed for easy conversion to either 5.7×28mm or 4.6×30mm cartridges.
U.S. manufacturer Knight’s Armament Company developed an experimental personal defense weapon chambered for a 6×35mm cartridge. The advantage of Knight’s round was its low recoil and reported ability to penetrate bullet proof glass and body armor at ranges out to 300 meters. The weapon developed by the company is similar in appearance to Colt’s M4 Commando, but with quite a few internal differences.
One of the Russian entries into the PDW field is the PP-2000, a weapon manufactured by the KBP Instrument Design Bureau. The PP-2000 was introduced during a 2004 exhibition in Moscow. Although the weapon is chambered for the 9×19mm round, it was specifically designed for use with the Russian 9x19mm 7N21 and 7N31 +P+ armor-piercing versions of the cartridge. The performance is reportedly comparable to the 5.7×28mm and 4.6x30mm PDW cartridges while still being able to use common 9x19mm rounds.
The MP9 is a compact weapon currently being manufactured by Brügger & Thomet of Switzerland. The MP9 is a selective-fire PDW chambered for the 9×19mm Parabellum round. The weapon fires from a closed, locked bolt utilizing a rotating barrel locking system. The MP9 is a development of the Steyr TMP. The design of TMP was purchased from Steyr in 2001. The primary difference is the TMP has a stock that folds to the right side of the weapon, an integrated Picatinny-style rail, and a trigger safety.
CBJ Tech firm of Sweden has developed a new 6.25x25mm cartridge with case dimensions similar to the 9×19mm Parabellum round. The primary purpose the cartridge’s development is to convert 9mm weapons into modern personal defense weapons with the ability to meet the NATO CRISAT body armor defeat criteria consisting of 1.6 mm titanium and 20 layers of Kevlar.
The cartridge round features a sabotted 4 mm tungsten sub-projectile. The 6.25x25mm round was engineered to produce the similar recoil and pressures to allow most 9mm weapons to be easily converted to 6.5×25mm CBJ by changing the barrel. The 9mm bolt is retained because the cartridge head diameter is also the same for both cartridges. The rounds are designed to fit and feed from the weapon’s original 9mm magazine. The firm also has designed a compact weapon chambered for the 9mm or 6.5mm round, the CBJ-MS personal defense weapon. SAAB-Bofors was initially involved in helping to market the 6.5x25mm but is no longer involved with the project. CBJ Tech is continuing to develop the ammunition and demonstrate its capability in a wide variety of converted submachine guns and pistols. However, CBJ Tech is now mainly focused on adapting existing 9mm weapons.