the round was fired from several hundred feet away. Due to the politically devastating nature inherent in this design, the S4M was kept highly secret. Information on the pistol was not known by western governments until well after the end of the Cold War. The Winchester Liberator is a 16-gauge, four-barrelled shotgun, similar to a scaled-up four-shot double-action derringer. It was an implementation of the Hillberg Insurgency Weapon design. Robert Hillberg, the designer, envisioned a weapon that was cheap to manufacture, easy to use, and provided a significant chance of being effective in the hands of someone who had never handled a firearm before. Pistols and submachine guns were eliminated from consideration due to the training required to use them effectively. The shotgun was chosen because it provided a high hit probability. Both Winchester and Colt built prototypes, although the Colt eight-shot design came late in the war and was adapted for the civilian law enforcement market. No known samples were ever produced for military use. Dual-use weapons Some purpose-designed insurgency weapons were designed for a dual use–that is for use by both insurgents and conventional soldiers. The Welrod pistol was a simple, bolt-action pistol developed by the SOE for use in World War II. It was designed for supplying to foreign British-aligned insurgents and for use by covert British forces. The pistol was designed with an integral sound suppressor, and was ideal for killing sentries and other covert work; the bolt-operated action meant that cocking the gun produced almost no noise, and the bulky but efficient suppressor eliminated nearly all of the muzzle blast. Welrod pistols included a magazine that doubled as a hand-grip, and were originally produced with no markings save a serial number. The Sten was a 9×19 mm Parabellum submachine gun manufactured by the United Kingdom in World War II. Although not designed as an insurgency weapon, it was designed at a time when Britain had a dire need for weapons and was designed to be easily produced in basic machine shops and use a readily available round, it was therefore the ideal weapon to be produced by resistance groups in occupied territories. Towards the end of the war, the German were in need of weapons and they produced both a version of the Sten, the MP 3008, to arm the Volkssturm and near identical copies of the Sten down to makers marks to arm the