Book excerpt: Since the mid-1960s the Heckler & Koch MP5 has become the most widely used submachine gun in the world, especially among counterterrorist and special-operations units. Lightweight and offering a blistering rate of fire of up to 900 rounds per minute, the MP5 quickly earned a reputation for accuracy. Fielded early by West Germany's GSG 9 counterterrorist unit it was soon adopted by the SAS. Today military and police agencies in over 80 countries from Albania to Zambia utilize the weapon. Featuring specially commissioned full-color photographs and expert analysis, this engaging study charts the origins, use, and impact of the MP5, Heckler & Koch's innovative and long-lived submachine gun.