The famous Danish company Dansk Industrie Syndicat AS 'Madsen', usually referred simply as Madsen or DISA, manufactured various weapons since the early 1900s. In 1946 Madsen introduced a modern submachine gun, the m/46, which featured an entirely stamped receiver, integral with pistol grip and magazine housing. This SMG also featured unusual charging handle, a bracket-shaped slider above the receiver. But the most unusual feature of the m/46 was the field stripping procedure. The receiver was made from two halves, left and right, hinged at the rear, and held together at the front by the screw-on barrel nut. To disassemble the gun, one must unscrew the barrel nut, and then open the left side of the receiver/housing. Barrel, bolt, return spring and trigger unit will remain in the right "half" of the gun, easily accessible. The hollow pistol grip contained magazine loading tool, and there were no manual safeties; instead, Madsen m/46 had an automatic safety in the form of the lever just behind the magazine housing; to fire the gun, one must grasp the magazine and this lever securely by non-firing hand, to be able to release the bolt. Otherwise, the m/46 was a fairy conventional blowback design, which fired only in full auto.
Following the initial success of the m/46, DISA introduced the M/50, a slightly modified M/46 with more conventional and comfortable charging handle at the top of the gun, and in 1953 Madsen introduced the last gun in this line, M/53, which differed mostly in that it used a curved magazines instead of straight ones, and can be fitted with optional barrel shroud, which had a bayonet mount lug. The M/53 Mark 2 version differed from all other guns in this line by having a fire mode selector. Madsen SMG's were sold to various Asian and South American countries. Brazil also manufactured a licensed copy of the Madsen m/50 in .45ACP caliber.