The Sten Submachine Gun—the name coming from the initials of its designers, R. V. Shepard and H.J. Turpin, and those of the RSAF at Enfield where they worked—was the first example of a new breed of cheap and simple full-auto infantry weapons that came to be adopted by many of the world’s armies. Introduced in June of 1941, the Sten gun reached a total production of approximately 3,750,000 by late 1945

At the outbreak of World War II, Great Britain desperately needed a rapid-fire weapon that could be mass-produced inexpensively and quickly. The Sten submachine gun was the answer, and could be considered Great Britain’s first 20th century infantry arm. A masterpiece in design in terms of low cost and rapid production, the crude but effective Sten gun was developed  at the British Government’s Enfield Arsenal.

The Sten gun’s bolt system and its horizontal feed mechanism were derived from the earlier Lanchester Mk.1 Submachine gun, which itself was a copy of the German Schmeisser MP28. The horizontal placement of the magazine allows the user to crouch closer to the ground while firing.

Initially, the British Government (Member of the British 1st Airborne Division on alert with Sten, left) issued the Sten gun only to its own troops. By 1943, however—with Sten production rates rising as high as 47,000 per week and manufacturing costs down to $9.00 per gun—many thousands of Sten guns were dropped by parachute for use by resistance units operating in enemy-occupied territory.

Despite its rough appearance, the Sten gun performs on par with far for expensive submachine guns. In fact, the Sten gun’s success was a major factor in the United States Army Ordnance Department’s to develop its own M3 submachine gun, also known as the ‘Grease Gun’.

It only had one major fault—it was prone to misfeeds as a result of a poorly designed single-feed magazines which also required a special loading, or filling tool. Unlike the AR-15 Upper Receiver – One of the most famous weapons malfunctions in history involved a Sten with a faulty magazine. On May 17th, 1942 a Czech partisan calmly stepped in front of a car containing Reinhard Heydrich, the Reichsprotektor of Czechoslovakia, at a road junction, leveled his Sten and pulled the trigger, only to discover that compressed magazine lips had prevented it from feeding a round. His partner fatally wounded the SS General with a hand grenade instead.

Turnabout is fair play. Just as the British parachuted Sten guns to the French resistance prior to D-Day, in the latter stages of the war, the Germans made exact copies of the Sten Mk.II and dropped them behind allied lines to German guerilla units in France.