Meanwhile, an USAF General, Curtis LeMay, witnessed a demonstration of the AR-15 in mid 1960 and became a proponent of the new weapon. Therefore, in 1961, he requested an order of 80,000 units for use by the Air Force. At that time, the US military was generally using the M14 rifle which fires a 7.62x51 mm. NATO cartridge. Hence, President John F. Kennedy, on the advice of US Army General Maxwell Taylor, stopped the AR-15 request on the grounds that having two different calibers within different military branches was a bad idea. However, another US government agency sent a batch of the new AR-15 rifles to South Vietnam, where it met with widespread praise by its users.
President Kennedy had appointed Mr. Robert McNamara as the Secretary of Defense at this point. Mr. McNamara was a former Ford Motor Company executive, who had risen up the ranks in Ford, becoming the first non-member of Henry Ford's family to become the president of the company. He had built his reputation by stopping Ford's losses in the late 40s and 50s by bringing in modern organization, management control and planning systems and was a big proponent of efficiency. Mr. McNamara started to push the various branches of the US military to adopt some common weapons, vehicles and aircraft to cut down costs (He was famously known as "Mac the Knife" in the Pentagon, for his cost-cutting measures). Now, after the enthusiastic reports about the AR-15 from South Vietnam, Mr. McNamara had to decide whether to believe the Pentagon's decision on sticking with the M14 or going with the positively glowing reports from South Vietnam about the new AR-15.
So he ordered Secretary of the Army, Cyrus Vance, to conduct tests between the M14, the AR-15 and the AK-47. The test results showed that the Army favored the existing M14, but then subsequent investigation showed that the testing methods were biased by the testers to favor the M14. In the end, Mr. McNamara ordered M14 production to stop in January 1963 because he determined that only the AR-15 could serve the needs of all branches of the US military. This was at a time when 5.56x45 mm. ammunition was not available widely, so the US Army tried to resist the change to the new rifle. The US Army also conducted a series of tests and wanted a few improvements done to the weapon:
- Adding a chrome lining the inside of the barrel and the firing chamber in order to resist corrosion and wear and tear.
- Adding a forward assist lever to push the rifle bolt into battery, in the event that a cartridge could not load into the chamber correctly due to corrosion or dirt.
- Cleaning kits for the rifles.
Colt insisted that the design was self-cleaning and needed no maintenance and in order to cut costs, the first versions of the new rifle were released with no cleaning kits or chrome lining. Colt and the US Air Force also didn't want to add the forward assist lever, because it added an additional $4.50 to the cost of each rifle, but the US Army insisted upon this change. In the end, Colt decided to produce two versions, a US Airforce version called the M16, which has no forward-assist lever and another version, called the XM16E1, with the forward assist lever, for the other military branches. The XM16E1 was renamed as the M16A1 by the US Army. In November 1963, Mr. McNamara approved the US Army's order for 85,000 M16A1s for the US Army and an additional 19,000 M16 models for the US Air Force.
The M16A1 was sent to equip US troops in Vietnam, in 1965. Almost immediately, reports of jamming issues and malfunctions began to emerge. In several cases, dead US troops were found with jammed M16A1 rifles. A Congressional investigation was launched and the key culprit emerged -- it was the propellant used for the cartridges. The original cartridges used during the evaluation tests were manufactured by DuPont and used nitrocellulose based powder. However, these cartridges could not be profitably mass-produced and their propulsive force was just a bit below the desired specifications, when used in arctic conditions. Hence, a new cartridge from Olin Matheson was used instead, which used a mixture of nitrocellulose and nitroglycerin. This new propellant caused dirtier residue than the propellant used in the original cartridges when the rifle was first evaluated. Due to the fact that the rifle came with no chrome lining or cleaning kit, build up of residue could cause jamming issues. The new cartridge also burned faster and therefore increased the rifle's firing rate from 850 to 1000 rounds per minute, which caused extra stress on the rifle's springs.
Once the issues were identified, the US military quickly added chrome lining and also added a buffer system to reduce the firing rate to 650-850 rounds per minute. Cleaning kits and maintenance instructions were also issued and the rifle's failure rate immediately dropped. However, the early reliability issues gave this rifle a bad reputation in the beginning, and this bad reputation continued to dog the M16 for some years afterwards, even after the issues were all fixed. By 1968 though, the rifle began to gain popularity from US soldiers. A 1968 survey among 2100 US soldiers showed that only 38 individuals had wanted to replace the M16 with another weapon and of those 38 people, 35 of them had wanted the CAR-15, a carbine version of the M16!
Other NATO countries also wanted to share commonality with US military firearms and hence, they all began to adopt the 5.56x45 mm. cartridge.
In the next post, we will study the development and insight into the design of the various M16 variants that followed the M16A1 model.