From Pistols to PDWs: How Modern Personal Defense Weapons Evolved

The emergence of personal defense weapons (PDWs) was neither accidental nor straightforward. It was the result of more than a century of attempts to strike the right balance between the compactness of a pistol and the effectiveness of a rifle. From modified World War I pistols to submachine guns, lightweight carbines, and Cold War experiments, each step addressed a specific problem—and revealed new limitations. Out of these trials and dead ends, the PDW concept gradually took shape as we know it today.

In the previous article, we explored the difference between submachine guns and PDWs and touched on the origins of two key examples—the FN P90 and the H&K MP7. As is often the case, however, the road to a workable solution was anything but smooth.

It’s also worth noting that what is—and isn’t—considered a precursor to the PDW is far from clearly defined. Over the past century, a wide range of pistols, rifles, and submachine guns have been modified or adapted to meet the need for more effective personal defense, or to fulfill roles for which standard-issue weapons were not suitable.

Let’s take a closer look at the developments that ultimately led to the weapons relied upon today by military and law enforcement units around the world.

World War I: The Search for a More Compact Weapon Begins

World War I—often referred to as the Great War—was “great” not only in terms of the lives lost and the scale of destruction it caused. It also marked a turning point in how wars were fought, reshaping tactics and strategy in ways never seen before.

The introduction of automatic weapons, early self-loading rifles, tanks, and aircraft fundamentally changed the battlefield. All of this unfolded against the backdrop of trench warfare.

British soldiers in a captured German trench during the Battle of the Somme (1916). The confined conditions of trench warfare exposed the limitations of long rifles and highlighted the need for more compact personal defense weapons. Photo: Lt. J. W. Brooke / Imperial War Museums (public domain)

The Limitations of Bolt-Action Rifles in Trench Warfare

In such conditions, the limitations of standard long bolt-action rifles quickly became apparent. They were heavy, unwieldy, and chambered in cartridges that were more powerful than necessary for the role. Their practical rate of fire was also limited. As a result, they were far from ideal for officers, vehicle crews, artillerymen, and other personnel not intended for front-line combat.

One option was to equip them with revolvers and increasingly popular semi-automatic pistols. Another was the submachine gun. By the end of World War I, however, submachine guns were still in their infancy and were primarily seen as offensive weapons for clearing trenches.

The pistol therefore seemed like a practical solution—but not always a sufficient one. Limited magazine capacity and short effective range were clear drawbacks. Shooting a handgun without a stock also required a level of skill that often exceeded the training of the average user.

Pistols as the First Practical Solution

Solutions to this problem appeared quickly, and one of the most iconic was the so-called “artillery model” of the Parabellum P-08 pistol. The standard P-08—better known as the Luger—was fitted with a longer barrel measuring around 200 mm, roughly twice the length of the original. Some variants even featured barrels up to 400 mm long. Adjustable sights were graduated out to 800 meters, which was rather optimistic for a 9 mm Luger cartridge.

The key feature, however, was the high-capacity 32-round drum magazine, along with the option to attach a shoulder stock. These additions significantly expanded the pistol’s potential as a personal defense weapon. They improved accuracy, increased rate of fire, and—thanks to the higher capacity—offered a level of firepower that was highly unusual for a handgun of the time.

The First Step Toward Greater Firepower

Another key predecessor in the evolution toward PDWs was the famous German Mauser C96 pistol—one of the first commercially successful semi-automatic handguns in the world. In addition to its detachable shoulder stock, which also served as a holster, the C96 was later adapted to accept higher-capacity magazines instead of its original fixed internal magazine.

With various barrel lengths, the C96 served alongside the Parabellum P-08. Notable versions included the M1917 “Trench Carbine.” A major step forward came in the early 1930s with the introduction of select-fire capability. The Mauser C96/712 Schnellfeuer earned a strong reputation—particularly in China—and also saw service during World War II.

Compact and capable of a rate of fire approaching 1,000 rounds per minute, it was a remarkably effective weapon for its size.

Detail of the Mauser C96 pistol, one of the first commercially successful semi-automatic handguns. Similar designs, often equipped with a detachable stock and higher-capacity magazines, are considered early predecessors of the PDW concept. Photo: Armémuseum (Swedish Army Museum) / CC BY 4.0

World War II: When Pistols Were No Longer Enough

World War II also played a key role in the development of what would eventually become PDWs. The need to equip vehicle crews, officers, and other non-frontline personnel with a more effective defensive weapon than a standard pistol remained very real.

The United States took an approach that, in many ways, foreshadowed the PDW concept of the 1990s. After adopting the semi-automatic M1 Garand—a major step forward at the time—it became clear that such a large and powerful rifle was not ideal for many roles within the armed forces.

M1 Carbine: A Lighter, More Compact Alternative

The result of this effort was the M1 Carbine—a lighter, more compact alternative to a full-sized rifle. It was a lightweight carbine chambered for the newly developed .30 Carbine cartridge. In appearance, the round resembled an elongated pistol cartridge rather than a traditional rifle round.

As we mentioned earlier, modern PDWs use cartridges that are essentially scaled-down rifle rounds. In this case, a similar result was achieved in the opposite way—by extending a pistol-style cartridge.

Compared to submachine guns, which were rapidly gaining ground in the arsenals of most armies during World War II, the M1 Carbine offered better range and accuracy while maintaining low recoil and manageable weight. Although it was not as compact as some of the German designs that could, in certain configurations, be carried almost like a pistol, it proved highly popular among troops.

An Intermediate Step Toward the Assault Rifle

Many also see the M1 Carbine as an early step toward what would later become the assault rifle concept. In many ways, assault rifles addressed the same issue—the lack of practicality of full-power rifles chambered in cartridges such as 7.92×57 mm Mauser or .30-06 Springfield.

Intermediate cartridges, including the well-known 7.62×39 mm, its successor 5.45×39 mm, and the 5.56×45 mm NATO, made it much easier to design weapons in a more compact and manageable form.

Over time, both sides of the Iron Curtain introduced a range of compact assault rifles aimed at bridging the gap between pistols and full-sized rifles. But that’s getting a bit ahead of our story.

The Cold War: The Emergence of Compact Automatic Weapons

The Postwar Search for a Compact Automatic Weapon

In the postwar period, attention once again turned to compact automatic weapons. The goal was to offer greater firepower than a pistol, without significantly increasing size.

In many ways, this approach built on earlier designs such as the Mauser Schnellfeuer and similar weapons.

APS Stechkin: Revisiting the Automatic Pistol Concept

In the 1950s, the Soviet Union developed several prototypes of automatic pistols chambered for the newly introduced 9 mm Makarov cartridge. The result was the adoption of the APS Stechkin pistol into Soviet military service. It was relatively large for a handgun of its time and featured a detachable stock that also doubled as a holster—much like the Mauser Schnellfeuer.

With a 20-round capacity and a rate of fire of around 750 rounds per minute, it offered a respectable level of defensive capability. It was intended for roles such as downed pilots, tank crews forced to abandon their vehicles, or officers operating behind the front lines.

In practice, however, the Stechkin proved less than ideal. Effective use required a relatively high level of training. Even so, it remained in service with the Soviet military for decades—and can still be seen in use on the battlefield in Ukraine today.

Škorpion: A Real Breakthrough in Compact Weapons

A true breakthrough among PDW predecessors came in the late 1960s—this time in Czechoslovakia. A young and promising designer, Miloslav Rybář, developed a prototype known as the Š-59. Just two years later, it entered service with the Czechoslovak security forces and armed forces as the vz. 61 “Škorpion.”

What made it such a breakthrough? Unlike earlier designs, it was conceived from the outset not as a pistol capable of automatic fire, but as a purpose-built compact submachine gun. Rybář himself described it as a “personal” submachine gun.

Despite its relatively unconventional 7.65 mm Browning chambering, the Škorpion offered impressive performance. Weighing just 1.28 kg, with 10- or 20-round magazines mounted outside the grip, a folding stock, and highly compact dimensions, it could be carried in a belt holster not much larger than that used for the vz. 52 service pistol.

In the years that followed, the Škorpion became widely used across various security and military forces. In Czechoslovakia, it was adopted by the National Security Corps, which had originally driven its development, as well as by the Czechoslovak People’s Army and the prison service.

The weapon also gained popularity abroad. Owing to its unique combination of compact size and firepower, it was valued by a wide range of users—including irregular and non-state groups.

By the mid-1980s, Česká zbrojovka in Uherský Brod had produced over 200,000 units. Production licenses were also sold to Yugoslavia, where it was manufactured under the designation M84 at the Zastava factory in Kragujevac.

Compact Submachine Guns Take the Stage

Throughout the 1960s, 1970s, and 1980s, a wide range of compact submachine guns began to appear. Most of them, however, were still larger than the Czechoslovak Škorpion.

In Poland, the PM-63 RAK combined an open-bolt system with a slide more reminiscent of a pistol. Chambered in 9 mm Makarov, it offered greater power than the Škorpion, but never achieved the same level of popularity or widespread use. It is occasionally seen in period photographs as a personal weapon carried by Palestinian leader Yasser Arafat.

In the United States, the Ingram MAC-10 gained significant popularity. It was another highly compact design with an impressive rate of fire. Available in multiple calibers—from the smaller M11 in .380 ACP to 9 mm Luger and .45 ACP—it found its way not only into military and law enforcement use, but also into the hands of criminals. Its notoriety was further amplified by frequent appearances in Hollywood films.

Israel followed with the Micro UZI. Unlike the Ingram, it fires from a closed bolt, but shares similarly compact dimensions and a rate of fire exceeding 1,000 rounds per minute. Over time, it underwent a number of refinements and remains in production today in its modernized form as the UZI Pro.

Finally, the German Heckler & Koch MP5K deserves mention. In contrast to the more utilitarian designs of its American and Israeli counterparts, it represented a different level of engineering. With its roller-delayed blowback system and high build quality, the MP5K has become a legend—and remains in use alongside its larger sibling, the MP5.

M1A1 Carbine with a folding stock for airborne troops. Developed as a lightweight, compact alternative to a full-sized rifle, it represents an important step in the evolution toward modern personal defense weapons (PDWs). Photo: Rama / CC BY-SA 3.0

An Alternative Path: Compact Assault Rifles

Alongside compact submachine guns, a number of manufacturers also explored compact assault rifles. These were typically shortened versions of standard service rifles, featuring folding or telescoping stocks and significantly reduced barrel lengths.

One example is the XM177, better known as the Colt Commando—a carbine derived from the M16 platform. Its barrel, shortened to as little as 10.5 inches, improved overall compactness. However, the recoil spring housed in the buffer tube limited further design options, particularly the use of a fully folding stock.

In the 1980s, the Soviet Union introduced a subcompact variant of the AK-74, known as the AKS-74U. Nicknamed “Krinkov,” it became one of the most recognizable compact rifles of its era.

Photographs from the Soviet–Afghan War show helicopter pilots carrying the AKS-74U in belt or thigh-mounted holsters. Even so, handling a weapon weighing around 2.7 kilograms and measuring nearly half a meter in length was far from practical.

The Shortcomings of Submachine Guns and Carbines

By the 1980s, however, it had become clear that both submachine guns and compact assault rifles had their limitations when it came to personal defense. Submachine guns were constrained by the performance of pistol cartridges, while shortened rifles remained relatively large and heavy for the role expected of a PDW.

This led to the idea of combining the strengths of both into a single weapon. The result was the class of firearms discussed in the previous article.

In the end, however, the PDW concept never achieved the level of adoption that had originally been anticipated. The relatively small number of true PDW designs suggests that they did not fully replace submachine guns or compact assault rifles in military and law enforcement service. Instead, they found their place alongside them—filling specific roles where their unique characteristics offered a clear advantage.