The MM-1 revolver grenade launcher is manufactured in USA by the Hawk Engineering Co, and is in use by Special Forces of USA, as well as of several South American and African countries. While MM-1 may look much like upscaled Milkor MGL grenade launcher, most probably the MM-1 traces its ancestry back to the Manville machine projector, a revolver-type 20-shot tear gas gun, developed in USA for police use before the World War II. The MM-1, while being relatively heavy and quite bulky, can provide devastating firepower, with practical rate of fire as much as 30 rounds per minute. It may be very useful in ambushes and other fast-pacing close combat scenarios.
MM-1 is a revolver-type weapon, with the heavy cylinder being rotated for each shot by the clockwork-type spring. Spring is wound manually during the reloading. To reload the cylinder, the rear part of the gun is released and rotated sideways to expose the rear of the cylinder, which is connected to the front part of the frame and barrel.