The Swedish K Submachine Gun Was So Great That the Americans Couldn’t Help But Copy It
A simple, reliable weapon
by MATTHEW MOSS
Gunnar Johnsson, an engineer at Carl Gustafs Stads Gevärsfaktori designed the Kulsprutepistol m/45 — sometimes known as the “Swedish K” — at the end of 1944.
It endured in military service for more than 60 years, making it a true classic. Demand was so high that, when Sweden cut off exports to the United States, an American company promptly copied it.
During World War II, neutral Sweden equipped its soldiers with the Husqvarna m/37/39, a licensed copy of the Finnish Suomi submachine guns. By 1944, Sweden was seeking a new submachine gun that it could produce cheaply and efficiently.
The Carl Gustaf factory developed the m/45 while Husqvarna offered a similar submachine gun, the FM44 — later, Hovea M49. Unsurprisingly the Swedish army selected the m/45 from the state-owned Carl Gustaf factory.
Final development and initial production of the m/45 began just after the end of the war. Initially the m/45 had a removable magazine housing, allowing it to use the m/37–39's 50-round quad-stack magazines. These proved unreliable, so in 1948 Carl Gustav developed a new 36-round double stack, single feed magazine.
Contemporary submachine guns such as the STEN and PPSh-41 influenced the m/45’s design. Johnsson aimed to apply the same simple but effective production methods that had allowed the Allies to produce millions of guns during the war.
Chambered in nine-by-19 millimeter, the m/45 featured a conventional blowback action inside a steel tube receiver. The m/45 had no safety mechanism, but the charging handle could hook into a safety cutout in the receiver to prevent firing.
The m/45 had 100-meter and 200-meter flip-up sights. The m/45 weighed 7.4 pounds unloaded and its side-folding wire stock reduced the weapon’s length to 21.7 inches.
When the Swedish army replaced the 50-round magazines, Carl Gustav developed a new model with a fixed magazine housing that took only the new 36-round magazines.
This second new model, the m/45B, also had smaller barrel shroud holes and a stronger buffer. The original models without added magazine housings are rare, as Sweden refitted almost all of them to be compatible with the new magazines.
The m/45C had a bayonet attachment on its barrel shroud. The Irish Defense Forces and the Swedish army adopted this version. Interestingly, the Swedes often selected the m/45C fitted with a bayonet for ceremonial purposes. A select-fire variant, the m/45D, was optimized for police use.
While the m/45 could use standard nine-by-19-millimeter ammunition, the Swedish military also developed a lead-core, steel-jacketed, brass-covered “penetrating” round — the m/39B — for the m/45. The round’s main downside was its tendency to increase the rate of barrel wear.
The m/45 was extremely popular with U.S. Special Operations Forces in Vietnam, including U.S. Navy SEALs and the CIA. They favored the weapon’s robust design, reliable magazine and its ability to fire immediately after being submerged in water. The fact that it wasn’t American-manufactured made it suitable for clandestine work.
There are also examples of the m/45 with integral suppressors.
The m/45 armed not only the Swedish and Irish militaries and U.S. commandos, but also the Estonian navy — and both Algeria and Egypt produced licensed versions. The Egyptian “Port Said” and “Akaba” submachine guns, manufactured by Maadi Factories, saw action during the Suez Crisis in 1956, the Six-Day War in 1967 and the Yom Kippur war in 1973.
Irish and Swedish troops attached to the U.N. mission to the Congo during the early 1960s also carried m/45s into battle.
Sweden placed an arms embargo on the United States in 1966 over America’s intervention in Vietnam and this ceased exporting the m/45 to U.S. forces. Seeing an opportunity, Smith & Wesson began producing the M76, a clone of the m/45, in 1967.
The M76 featured several changes compared to the m/45. The pistol grip and trigger group were farther forward and it boasted a safety switch instead of a bolt safety slot.
The Swedish army retired the m/45 from service in 2007. however, it may still be in limited use with the Swedish Home Guard.
Originally published at www.historicalfirearms.info.