M75 grenade launcher

The M75 is a 40mm automatic grenade launcher that was used primarily as an aircraft weapon in United States service and was one of the first weapons to use the high velocity 40x53mm grenade.

Overview

Development of the M75 began in the late 1950s by the Ford Aerospace Corporation (sometimes referred to in this time period of Philco-Ford). While 40mm low velocity grenades were being developed for infantry use, the M75 was to be an aircraft weapon using a higher velocity grenade for additional range. While an aircraft gun pod was developed for it designated the XM13 [United States, 1969. p. B-3] , it would see far greater use as a helicopter weapon, mainly during the Conflict in Vietnam. The most notable systems were the M5 used on the UH-1 Iroquois, the XM8 used on the OH-6 Cayuse, and perhaps most notably as part of the turreted M28 system used on the AH-1 Cobra. In the last case the weapon was quickly replaced by the improved M129 launcher.

Design

The weapon is described as an "air-cooled, electrically powered, rapid firing weapon." [United States, 1969. p. F-4] All portions of the firing cycle are powered this way and the unit requires an external power source. Other important features are the reciprocating barrel and cam assembly that drive the other components of the system. [United States, 1969. p. F-4] The weapon accepts linked ammunition, which was fed from a rotary drums in the case of the M5 and M28 systems, and from boxes in the case of the XM8 and XM9 systems. [United States, 1969. p. F-4-5, H-7] The M5 could also use a box magazine.

Derivatives

While the M75 had no variants, Ford Aerospace developed an improved derivative, the M129, which quickly supplanted the M75. The M129 was effectively a redesign of the older weapon to incorporate a concentric cam and improved mount, as well as, a higher rate of fire of 400 rpm. ["US Army TACOM-RI". 5 October 2005 [http://tri.army.mil/LC/CS/csa/aaarmsys.htm U.S. ARMY HELICOPTER WEAPONS] . Access Date: 25 January 2008] The M129 was used in the aforementioned XM8 and M28 helicopter armament systems, as well as, the XM51 for the ill-fated AH-56 Cheyenne, and being trialed as a door gun for the UH-1 series with the XM94 system. Operation of the weapon is extremely similar to that of the M75, with the reciprocating barrel and cam assembly still presenting itself, and the weapon still being electrically driven. [United States, 1969. p. H-7-8]

References

Citations

ources

* Gervasi, Tom. "Arsenal of Democracy III: America's War Machine, the Pursuit of Global Dominance". New York, NY: Grove Press, Inc, 1984. ISBN 0-394-54102-2.
* Gunston, Bill. "The Illustrated Encyclopedia of Aircraft Armament". New York, NY: Orion Books, 1988. ISBN 0-517-56607-9.
* United States. Headquarters, Department of the Army. "FM 1-40 Attack Helicopter Gunnery." Washington, DC: Headquarters, Department of the Army, 1969.

ee also

* List of crew-served weapons of the U.S. Armed Forces
* Mk 19 grenade launcher
* United States 40 mm grenades
* U.S. aircraft gun pods
* U.S. Helicopter Armament Subsystems

External links

* [http://www.globalsecurity.org/military/systems/aircraft/systems/m75.htm M75 40mm Grenade Launcher - Global Security]
* [http://www.globalsecurity.org/military/systems/aircraft/systems/m129.htm M129 40mm Grenade Launcher - Global Security]
* [http://tri.army.mil/LC/CS/csa/aawpns.htm TACOM-RI U.S. Army Helicopter Weapons]