Car Company Had a Big Hand in Making the M16 Rifle

Marine with M-16 rifle

This article is sponsored by General Motors.

When you think of General Motors, you think of automobiles, not rifles. But the carmaker's Hydra-Matic division played a big part in manufacturing the M16 -- the most widely used infantry weapon in the history of the U.S. military.

In 1948, after analyzing three war's worth of bullet-hit data, the Army's Operations Research Office determined the service needed a rifle with low recoil that fired a small number of rounds. In 1957, the Army awarded contracts to Winchester and Armalite to design weapons that could penetrate both sides of a standard Army issue helmet at 500 meters with a magazine of 20 rounds that weighed around six pounds. The rifles also had to have automatic and semi-automatic firing modes. Armalite's AR-15 won the competition, and the Pentagon rebranded it as the M16.

In late 1959, Colt obtained manufacturing and marketing rights, and a few years later, the company got the Pentagon's Advanced Research Projects Agency to test 1,000 weapons as part of Project Agile -- a Defense Department weapons initiative focused on potential fighting in southeast Asia, which was becoming more of a possibility at that point. The Army wasn't particularly impressed with the early version of the rifle, but the ever-controversial Defense Secretary Robert McNamara ignored its input and ordered 85,000 for the Army and 19,000 for the Air Force.

But the early versions of the rifle had significant reliability problems, mostly around the fact that they had a tendency to jam in the tough conditions that went with the battlefields of Vietnam. Word circulated across the rumor mill that many troops disliked the new weapon so much that they bypassed it in favor of the older and heavier M14.

The bad press reached the Hill, and a congressional committee demanded answers. The lawmakers eventually forced the Army to do something about the situation -- both real and perceived. The result was the U.S. Army Weapons Command's issuing of a new set of requirements beyond what the original M16 design demanded. The new weapon -- labeled "M16A1" -- required a chrome-plated chamber to prevent rust, better powder and an additional 10 rounds in the magazine, bringing the total to 30.

Enter GM's Hydra-Matic division, the organization that got the nod to answer DoD's emergent need.

The organization that would become Hydra-Matic Division was founded in May 1939 as Detroit Transmission Division. It was created to continue the developmental work begun by Cadillac engineering and to manufacture the newly developed Hydra-Matic automatic transmission.

In 1953, following a fire at its plant in Livonia, Michigan, the Detroit Transmission Division moved into a leased facility near the Willow Run Airport in Ypsilanti that once housed a World War II bomber plant. It was at this facility in Ypsilanti that the M16A1 was manufactured. In 1962, DTD officially changed its name to the Hydra-Matic Division. The division would later be combined with the GM Engine Division to form the GM Powertrain.

In view of what the government called an "urgent need," Hydra-Matic management instituted a "crash" program. Part of this effort required GM's team to go to various government storage depots around the country to find the necessary machine tools in order to get the rifles out the door in a hurry without compromising on the military's requirements. Ultimately, they obtained more than 1,000 machines that Hydra-Matic housed in a 348,000-square-foot facility.

GM shipped the 100,000th rifle to the Army in September 1969, two months ahead of the required schedule. A year later, the company had delivered another 140,000 rifles. The company was awarded a second contract, and eventually the tally hit 469,217 M16A1s provided to the Pentagon.

The M16 underwent additional mods in the years that followed, including the development of a shorter-barreled version that has been extensively used by special operators in the wars in Iraq and Afghanistan. But arguably, GM's model gave the weapon what it needed to become an icon of military hardware.

The M16 in action: Video Center

For more on GM and its contributions to the U.S. military throughout history, visit the GM Military History page.

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