Side-fed Subguns: going sideways
In modern times, the side-fed submachine gun has largely been replaced by bottom feeders. But for a significant part of the 20th century, manufacturers primarily produced side-loaders for military service. Let’s take a look at some iconic subguns.
Early Development of the Submachine Gun
When the First World War broke out in August 1914 the nations of Europe marched off to the front lines armed with bolt action rifles. Most expected it to be a short conflict that would at least temporarily resolve territorial disputes on the continent. After the failure of the German Army at the Marne in September, both sides dug in and sought to hold the ground. This was necessitated due to a relatively new weapon on the battlefield – the machine gun.
Within a year the front lines were transformed into a hellscape of mud-soaked trenches stretching from nearly the English Channel to the Swiss Alps. New technology was introduced over the course of the four-year conflict to break the lines and turn the tide. This new technology included poison gas, combat aircraft (including bombers), and most — notably — tanks.
However, trench warfare also resulted in the development of portable machine guns and automatic weapons. These included the French Chauchat, the American-designed Lewis Gun, the American Browning Automatic Rifle and most notably the German MP18 (Maschinenpistole 18/I).
MP 18: First of the Side-Fed Subguns
Beginning in 1915 German designers at Theodor Bergmann Abteilung Waffenbau – including Hugo Schmeisser – worked to develop a compact “machine pistol.” This included attempts to modify the Luger and C96 Mauser for fully automatic fire. Those handguns were unable to handle the high rate of fire, so a new weapon was designed and this became the MP18.
It wasn’t technically the first submachine gun (SMG), as the Italians had already developed the Villar-Perosa as a light machine gun for use in aircraft. However, the MP18 was the first purpose-built SMG. Unlike the automatic rifles of the day including the French Chauchat and American BAR, the MP18 featured a side-loading magazine.
The rationale was that such a weapon could allow a soldier to stay lower to the ground. The MP18 also initially used a 32-round detachable drum or “snail” magazine that had been developed for the Luger pistol. Such a magazine would have been cumbersome underneath the receiver and would have blocked the sights if the weapon loaded from the top.
MP18 Submachine gun
Placing the magazine to the left created a slight balance issue when the gun was aimed, but this placement kept the magazine out of the sightlines of the shooter. More importantly, because the weapon extracted fired rounds to the right this caused it to pull up and to the right as well. In this case, the placement of the magazine actually helped steady the gun somewhat.
Interestingly, the MP18 was developed to use a conventional 20-round “box” magazine, but it was decided during testing that the snail drum magazines would provide additional ammunition. However, when the weapon was updated as the MP28 (Maschinenpistole 28/II) it was only used with box magazines.
Submachine Guns: More iconic side-fed weapon
The subsequent German SMG designs that followed the MP28 essentially refined that weapon. These included the MP34 (Maschinenpistole 34), which was designed by the Rheinmetall company in Germany. However, due to restrictions placed on Germany by the terms of the 1919 Treaty of Versailles, Rheinmetall acquired the Swiss company Waffenfabrik Solothurn to develop a prototype.
Rheinmetall then took a controlling interest in the Austrian firm Waffenfabrik Steyr to manufacture the weapon for both commercial and military markets. The MP34 was manufactured from some of the very best materials available at the time, featuring highly machined parts. The downside was that the production costs were very high, and due to this fact it has been dubbed the “Rolls Royce of submachine guns.”
The MP34 featured an open bolt blowback design and had a 600-rounds-per-minute rate of fire. Both 20- and 30- round box magazines were available for the firearm. While it was of extreme quality it was too expensive to mass-produce as the German military rearmed but it did remain in use with German Police and Waffen SS units during the war. It was also tested by the Japanese, and it was also used by the Portuguese military in its colonies after World War II.
Another German design from the early 1930s was the EMP (Erma Maschinenpistole), which was designed by Heinrich Vollmer and provided at the Erma (ErfurterMaschinenfabrik) factory. It was also an evolution of the MP18, but this design initially featured a wooden handgrip and loaded from a 25-drum magazine. As the design evolved the front handgrip remained, but the drum magazine was replaced with a 32-round box magazine. It had a 550 rpm rate of fire and featured a simple blowback operation.
The SS and German police units adopted the EMP, and this particular gun was widely exported. It saw use with both the Nationalists and Republicans in the Spanish Civil War. Thousands had been sold to Yugoslavia. Ironically, Yugoslavian and Chetnik forces used the German-designed weapon against the Germans.
One largely forgotten German-designed side-fed SMG was the MP35 (Maschinenpistole 35), which was developed in the early 1930s by Emil Bergmann and manufactured at the Bergmann company’s factories. What set this gun apart from other SMGs of the era was that the magazine was inserted from the right-hand side of the weapon, but why Emil Bergmann opted for this positioning is unknown. However, it has been favored by left-handed shooters as a result.
Bergmann’s MP35 Submachine Gun: feeding from the wrong side
The MP35 was developed with proprietary magazines, but when production was ramped up it was modified to utilize MP28-compatible magazines. It had a 540 rpm rate of fire. While never adopted by the Germany Army it was used by the SS and German police units and exported to numerous countries.
MP38 – MP40
The development of the MP38/MP40 – the SMG most associated with the German military in World War II – marked the end of the side-loading SMGs to come out of Germany. From that point forward German submachine guns have all fed from the bottom.
However, there was one final German weapon that utilized a side-feed magazine, the FG42 (Fallschirmjägergewehr 42, “paratrooper rifle 42”) – a select-fire automatic rifle. Developed specifically for use by the German paratrooper units, the FG42 combined the firepower of a light machine gun with a rifle. Unlike the aforementioned SMGs, which all were chambered in the 9mm Luger, the FG42 fired the full-size 7.92x57mm Mauser round. The weapon, which was actually produced in two different versions, featured a left-hand side loading feed system with either 10- or 20-round box magazines and it had a rate of fire of upwards of 900 rpm.
Other Side-Fed Submachine Guns
Germany was not the only nation to develop SMGs that loaded from the side. Brittain and Japan developed their own versions too.
The British military essentially copied the MP28/II with its Lanchester, which was manufactured by the Sterling Armaments Company from 1941 to 1945. While primarily used by the Royal Navy and to a lesser degree by the Royal Air Force, it actually remained in use until the 1970s!
It was noted for its high-quality materials and solid wooden stock, which was actually based on the Short-Magazine Lee Enfield’s stock. The weapon had a 600rpm rate of fire and was used with either a 32- or 50-round box magazine.
STEN Gun: Shepherd and Turpin’s side-fed submachine gun
Of course, the Lanchester has been largely overshadowed by the StenGun, which the British developed to equip its army after the fall of France. The weapon’s name comes from its chief designers Major Reginald V. Shepherd and Harold Turpin, and EN for Enfield. More than four million Sten Guns in various versions were produced and the weapon remained in use through the Korean War.
While considered simplistic and even “cheap” compared to the more robust German weapons, the Sten performed quite well. It featured a blowback operation and fired from an open bolt. It had a rate-of-fire ranging from 500 to 600 rpm and fired from a 32-round detachable box magazine. The Sten fired the 9x19mm Parabellum Luger round and was designed to accommodate the German MP40 magazine.
Type 100: a Japanese SMG
The Japanese military also sought to develop a submachine gun during World War II. Although it had tested the MP34, it produced the Type 100, which featured a wooden stock and uniquely a curved magazine that held 30-rounds. The weapon featured a blowback action, and was initially developed to fire just 450 rounds-per-minute, but the rate of fire was upped to 800 rpm in 1944. Only about 8,500 Type 100 SMGs were produced during the war, making it among the rarest of WWII small arms for collectors today.
Side-Fed Submachine Guns After WWII
After World War II most SMG development focused on bottom-feed systems – with many weapons taking cues from the German MP40. This included the French MAT-49, Zastava M56, Swiss MP48, Portuguese FBP, Belgian Vigneron, and even the American Smith & Wesson M76.
However, the British military developed one of the final side-loading SMGs during the war. George William Patchett, chief designer at Sterling Armaments Company, helped create a refined weapon that improved upon the Sten design but remained compact and easy to produce. The weapon became the Patchett Machine Carbine Mk1, and a prototype saw action in November 1944.
After the war, the gun evolved, and it was officially adopted by the British Army in 1951 as the Sub-Machine Gun L2Ai but was more commonly known simply as the Sterling. More than 400,000 were produced from 1953 until 1988, when it was finally phased out in favor of the L85A1 assault rifle, a weapon that instead of featuring a side-loading magazine is a “bullpup” with the magazine receiver fitted in the stock.
The Sterling featured a lever-delayed blowback and a 550 rpm rate of fire. It was fed from a curved 34-round magazine. In addition to being used by the British Army, and seeing service in the Suez Crisis, Mau Mau Uprising, the Troubles in Northern Ireland and the Falklands War, it was also carried by Imperial Storm Troopers in the Star Wars films!
Comments from the crowd – this treatise hardly covers all side-fed subguns. Which one(s) would you like to shoot if you had the chance?
Peter Suciu is a Michigan-based freelance writer who regularly covers firearms related topics and military history. As a reporter, his work has appeared in dozens of magazines, newspapers, and websites. Among those are Homeland Security Today, Armchair General, Military Heritage, Mag Life, Newsweek, The Federalist, AmmoLand, Breach-Bang-Clear, Newsweek, RECOILweb, Wired, and many others. He has collected military small arms and military helmets most of his life, and just recently navigated his first NFA transfer to buy his first machine gun. He is co-author of the book A Gallery of Military Headdress, which was published in February 2019. It is his third book on the topic of military hats and helmets.