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The SMG has been a gallant and important part of firearm history… until now.

This year, the submachine gun (SMG) is 100 years old and is rightly celebrated for being one of the most famous and influential weapon concepts in history. Although the Italians inadvertently created the SMG with the 9mm Villar Perosa in 1915, they foresaw it as an anti-aircraft weapon, rather than a handheld infantry arm. Visual examination of the weapon today quickly discloses that it’s essentially a second-generation design and was thus way ahead of its time.

But back in 1915, no such analysis was forthcoming.


Honors for being the first dedicated SMG must go to German arms designer Theodor Bergmann, whose 9mm MP-18 first appeared in 1918 and saw actual combat in the latter days of World War I. The MP-18 and subsequent other first-generation SMG designs were beautifully machined examples of the gunmaker’s art.


1918—MP-18 (Germany, Theodor Bergmann), the first practical, intentionally-designed SMG.

Yet, such quality was expensive and time-consuming—issues every military organization vehemently seeks to reduce. Nonetheless, the MP-18 continued in service throughout the 1920s and 1930s and served well into World War II.

The sheer number of SMGs produced during World War II guaranteed it would remain in service for decades to follow.

On this side of the Atlantic, General John T. Thompson’s .45 ACP M-1921 caused quite a stir when it was unveiled and was thought to be a harbinger of great things to come. Yet, unfortunately, because World War I was widely considered to be “the war to end all wars,” military budgets were slashed to the bone; and, for the entire decade of the 1920s, small-arms acquisition and development were at a virtual standstill.

By 1940, the Thompson had evolved into two distinct military versions: the M-1928A1 and simplifi ed M-1/M-1A1. Both saw worldwide action during World War II in the hands of Allied forces. (Photo: Stowe/Dreamstime)

As a result, while everyone lauded the weapon, itself, sales of the M-1921 Thompson were quite slow, and the resulting financial strain on its parent company, Auto-Ordnance Corporation, was extreme. To illustrate how bad Auto-Ordnance‘s predicament was: Of the original 15,000 M-1921s produced, by 1938, only 3,500 had been sold!

The problem was simple, but at the time, it was impossible to overcome. Like all first-generation SMGs, the Thompson was expensive and time-consuming to manufacture, meaning that its per-unit cost was high. When one considers that a Ford automobile sold for $400 at the time, the $200 retail price tag of an M-1921 Thompson was so high that it was considered to be “out of sight.” Even the later M-1928AC (although its price had been reduced to “only” $175) failed to excite the market to any significant degree. After the stock market crash of 1929, the worldwide economy cratered, and the phrase, “Times are hard,” became legion. No one, not the individual citizen, the state or federal government, had any money to spare.

Thus, the Thompson’s first action was in the hands of the Irish Republican Army (which bought 683 of them surreptitiously through a “straw man” buyer), the various gangs of the “beer wars” of the 1920s (which had the money) and then, in the 1930s, “motorized bandits” such as Bonnie and Clyde, John Dillinger and Lester “Babyface” Nelson (who regularly stole them from police armories). Even Auto-Ordnance Corporation’s new sale slogan, “On The Side Of Law And Order,” failed to generate much business, because even though small quantities were purchased as a result, the vast majority of police departments simply didn’t have the budgets to afford expensive weapons such as the Thompson.

General John T. Thompson during a demonstration of his famous .45 ACP M-1921 Thompson SMG.


The rise of German, Japanese and Italian militarism during the second half of the 1930s initiated a new look at small arms, and it became immediately apparent that first-generation submachine guns simply had to be made cheaper and faster. The result of this review was the first of the second-generation SMG: the 9mm MP-38/40. Constructed mostly of sheet metal stampings, spot welds and phenolic resins, the M-38/40 heralded a major breakthrough in SMG technology and caused it to proliferate wildly. Indeed, as World War II entered its second year, the 7.62x25mm Russian PPSh-41 and 9mm British STEN saw the beginning of large-scale production that continued throughout the war.

At that time, the United States was somewhat behind, in that it had finally adopted the M-1928A1 Thompson as its “standard” SMG in 1939. But it was quickly realized that it was too expensive and, in 1940, the Army entered into a massive program to simplify it and cut production costs and time. The result was the M-1/M-1A1 Thompson, which continued in production until late 1943. In comparison to the $175 per unit price tag of the M-1928, the $42 unit price of the M-1A1 reflected a substantial savings. Nevertheless, a review of the German MP-38/40 by the U.S. military resulted in a crash program to create a U.S.-made, second-generation SMG.

The result was the M-3/M-3A1 “grease gun,” which officially began to supersede the Thompson in 1944. The sheer numbers of SMGs produced during World War II were staggering: tens of millions were in circulation by 1945. Thus, the postwar years saw them appearing virtually all over the world in the various dirty, little wars that took place from 1945 to the end of the Cold War in 1991. U.S. law enforcement agencies had kept their beloved Thompsons, of course, but seldom used them in the field, so they never exhibited any significant amount of wear and tear. Even today, there are still Thompsons in many police inventories, although more-modern designs have overshadowed them.


The Arab-Israeli war of 1967 saw the first widespread use of a third-generation SMG—the 9mm UZI. Utilizing a telescoping bolt, the UZI was much shorter than any first- or second-generation SMG; and with the addition of a folding buttstock, it was quite compact. Shortly thereafter, an American designer, Gordon Ingram, unveiled his M-10, which took the concept even further. Available in both 9mm and .45 ACP, the M-10 wasn’t much bigger than a pistol and featured a threaded barrel to allow a sound suppressor, as well.

The Ingram M-10 (shown with sound suppressor) in both 9mm and .45 ACP first appeared in the late 1960s and quickly became famous as a military covert ops weapon (and, later, notorious in the hands of the drug cartels).

In the late 1960s, Heckler & Koch introduced the first fourth-generation SMG—the 9mm MP-5. It outwardly looked like a sophisticated second-generation design, but the MP-5 fired from a closed bolt like a standard self-loading rifle. All previous generations had fired from an open bolt in the mistaken—but universally accepted notion that sustained automatic fire would cause “cook-offs” from the heat generated. Oddly enough, the notion persisted without being questioned for more than 50 years before it was discovered that none of the pistol cartridges utilized in SMGs generated enough heat to cause a problem. Thus, the accuracy-degrading “slam-fire” lurch of all previous SMGs to push a puff of cool air down the bore was quickly shown to be invalid.

The proliferation of body armor since 2000 caused the development of smaller-caliber, high-velocity SMG cartridges. Heckler & Koch’s MP-7 and FN’s P-90 (below) reflect this trend.

This opened up a new vista of second- and third-generation SMG designs utilizing the closed-bolt principle. Back in the 1990s, Heckler & Koch subsequently created the UMP and then the MP-7, both of which fire from a closed bolt. The 9mm Czech Scorpion EVO 3 and Kriss Vector that have appeared in the last 15 years also utilize the concept. Because of its firepower and handiness, the SMG saw worldwide proliferation and became a standard item in both military and police inventories.

Also appearing during the last decade, the 9mm Kriss Vector SMG exhibits an ultramodern design that has caused it to be used in a multitude of motion pictures.

However, toward the end of World War II, the Germans introduced the first assault rifle—the 7.92mm StG-44—that effectively took over the role of both the SMG and standard infantry rifle. Technically, this made both obsolete, but the sheer quantities of SMGs made, along with their distribution to virtually every country during that war, ensured a long life span. Indeed, SMGs continue to be encountered on a  regular basis, war after war, conflict after conflict.


Because of the increased incidence of body armor, it became apparent that typical SMG ammunition lacked sufficient penetration for reliable target neutralization, so smaller-caliber cartridges, such as H&K’s 4.6x30mm and FN’s 5.7x28mm, appeared.

However, it was subsequently discovered that while they penetrated soft armor quite satisfactorily, their small calibers have often lacked stopping power. Thus, by all appearances, the SMG has reached the high point of its career. Even so, its limitations are more apparent than ever and cannot be overcome.


On the other side of the coin, the assault rifl e has evolved to the point at which it is the same size or smaller than the SMG and, in most cases, it is the same weight or lighter. The United States adopted the 5.56x45mm back in 1963, and it has since become the standard service cartridge of all the non-former Soviet nations, which still utilize the 7.62x39mm and later, the 5.45x39mm.

So, as the limitations of typical SMG cartridges became more obvious, and (in the United States, at least) the availability of M-16s and M-4s to law enforcement agencies radically increased, the 5.56 has steadily increased in popularity. The 5.56 easily penetrates soft body armor—but, with properly selected bullet designs, it is actually less penetrative through walls, etc., than a typical 9mm or .45 ACP bullet. And with its increased velocity, even from a short barrel, frangible bullet expansion is virtually guaranteed, whereas with a 9mm or .45 ACP it is not.


Therefore, it isn’t surprising that shortening a 14.5- or 16-inch-barrelled M-4 to, say, 10.5 or 11 inches to enhance
the weapon’s handiness would occur. That, indeed, happened during the Vietnam War with the XM-177E2. Known as the CAR-15 by those who carried and used it during that conflict, its handiness and light weight made it much sought after, although it was actually issued only to Special Operations and other test units.

The current iteration of the XM-177E2 is based on the standard M-4A1 platform and is becoming highly popular among both military and police Spec Ops personnel. (Photo: U.S. Navy)

Today’s short-barrelled M-4A1 is a direct spinoff from the XM-177E2 and is seeing rapid proliferation
throughout the Spec Ops world. By all estimates, the need for such short-barrelled carbines is increasing. As a result, many manufacturers around the world have begun offering their own versions: Heckler & Koch’s M-416 FC and G-36C, SIG’s MCX and SIG556 SBR, and Israel Military Industries’ G-2SBR are classic examples of this trend. Former Soviet nations, all of which are well indoctrinated to the AK-47, are also adopting shorter-barrelled versions, such as the AMD and AKS-74U (called the Krinkov in the United States), in both 7.62x39mm and 5.45x39mm.

During the last decade, U.S. military and other Spec Ops forces are increasingly seen with short-barrelled M-4A1s–and why not? The handiness, light weight and superior “human engineering” of such weapons are undeniable. They’re the same size and weight as most SMGs but are more powerful and versatile.

Within the next decade or two, the SMG will… most likely gradually fade away. It has been a gallant and important part of firearm history.

The M416 FC and G-36C (below) are Heckler & Koch’s current entries into the burgeoning 5.56 SBR market.


The answer: No. But it’s definitely ailing and, I think, is reaching the end of its life span. Its limitations make it a less-attractive and -useful weapon than the short-barrelled carbine. The latter is more powerful, just as easy to control and carry, and allows effective target engagement at ranges far beyond those possible with any SMG. Consequently, we’re seeing it relegated more and more to urban police functions, with more departments and more agencies replacing them with SBRs as their SMGs reach the end of their service lives. Within the next decade or two, the SMG will, therefore, most likely gradually fade away. It has been a gallant and important part of firearm history.

Israeli Military Industries’ 5.56mm G-2SBR is also based upon the M-4 and is beginning to see considerable service with Israeli Special Forces and other elite units.

Editor’s note: A version of this article first appeared in the May 2017 print issue of Gun World Magazine.