The M4 model of the Carl-Gustav recoilless rifle series was debuted in 2014 by Saab Bofors Dynamics of Sweden. It is a multirole solution, able to counter armored vehicles and fortifications as well as infantry using variable warhead types. The design relies on a "recoilless rifle" approach in which some of the resulting propellant gasses of the igniting round are forced out of the rear of the launch tube, countering the natural recoil of the outgoing projectile at the front. The rifled barrel imparts stabilization to the exiting projectile which is further fin-stabilized along its flight path. The first Carl-Gustav launcher emerged in 1946 following the close of World War 2 (1939-1945) and the improved M2 followed in 1964. A more modern design was revealed in 1991. The M4 represents the latest incarnation of the storied Carl-Gustav recoilless rifle line offered by the Swedish concern with the weapon remaining popular within many circles across the globe.
The M4 has been developed with urban warfare in mind, becoming a lighter weight (thanks to use of carbon fibers) and shorter weapon system than seen in previous Carl-Gustav launcher iterations. It weighs a manageable 15 lb, down from the 19 lb of the M3, and showcases an overall length of 950mm from the M3's 1,100mm design. Other additions include a section of Picatinny rail for the implementation of various user optics, reworked ergonomics that include a foregrip and shoulder rest, and a "shot counter" telling the operator or inventory manager how many shots have been fired from the tube (the tube is rated for 1,000 lifetime shots).
In practice, the compact, lightweight weapon can be fielded by a single person though two persons attached to a single unit provide increased efficiency in the warzone (rate-of-fire can reach six rounds per minute). The projectile is an 84x246mmR caliber round that can deliver various warhead types - HEDP (High-Explosive, Dual-Purpose), HEAT (High-Explosive, Anti-Tank), HE (High-Explosive), flechette (anti-personnel), illumination, and smoke (as well as training rounds) - to cover many battlefield roles - Anti-Armor, Anti-Structure, Support, Anti-Personnel, and possible future rounds yet-to-be-developed. Iron sights are provided but optics typically used and these include a red dot sight, a telescopic sight, or intelligent sighting device as well as laser rangefinders and image intensifiers depending on mission role - making for an all-around outstanding weapon for standard infantry groups or special forces units. The weapon is also prepared for "programmable" rounds - the future of land-based warfare - and has a "safely loaded" design which allows the operator to carry the launcher with the ready-to-fire projectile chambered, offering quick-reaction times to emerging battlefield threats.
The M4 is under consideration by SOCOM forces of the United States military. If adopted it would carry the designation of "M3A1". The Carl-Gustav M3 is already in inventory with the Americans as the M3 MAAWS ("Multirole Anti-armor, Anti-personnel Weapon System").