M129
Overview
M129
M129 automatic grenade launcher.
Source: US Army -
© Public domain
Description
Introduction
The M129 is an early Cold War era automatic grenade launcher of US origin. It is a product improved version of the earlier M75. It has been made more reliable and has a higher rate of fire. The M129 can also fire both high and low velocity 40mm grenades, although the high velocity type is the default.
Design
The M129 uses the same operating mechanism as the earlier M75. The whole firing cycle of the weapon is electrically powered by a single electric motor. This is fed by an external power source. A cam assembly located in a drum actuates all moving parts and the feed cycle. Upon firing the barrel reciprocates. The main difference on the M129 is that the barrel is located within a larger actuating drum, reducing torque and improving reliability. Rate of fire is increased.
Firepower
The M129 fires the 40mm grenades at a cyclic rate of fire of 320 to 440 rpm. Maximum range is about 1.9 km using the 40x53mm high velocity grenade, which is the default ammunition type. Alternatively the low velocity 40x46mm grenades can be used, which were intended for single shot grenade launchers carried by the infantry.
Platforms
The M129 is best known for being one of the weapon types used in the M75 twin gun turret of the AH-1 Cobra. Often one 40mm M129 was used alongside a single 7.62mm M134 minigun. Other helicopter mounts include the XM8 system for the OH-6 Cayuse and OH-58 Kiowa. This is a single gun setup with 150 rounds of ammunition. The XM94 pintle mount could be fitted on either side of the longer fuselage Bell 205.
Users
The main user of the M129 was the United States. The M129 was actively used as helicopter armament during the Vietnam war. Exports to various nations were made as part of helicopter armament. This included sales of the AH-1 Cobra and pintle mounts for helicopters such as the Bell 205.
Details
Media
M129
M129 automatic grenade launcher seen on M94 armament subsystem. This can be mounted on helicopters to be manned by a door gunner.
Source: US Army
Copyright: Public domain
M129
M129 automatic grenade launcher mounted inside the M28 chin turret of an AH-1 Cobra attack helicopter.
Source: Unknown author, possibly Charles Jackson
Copyright: Public domain
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Mk 19 MOD 3
The M129 was fielded at the same time as the Mk 19, which was intended for ground use.