So much has been written about the M16 that it is impossible in a short review to cover a great deal of it, but here goes!

The M16A1 started out in the late fifties as the brainchild of aerospace enginee Eugene Stoner, who together with the Fairchild aircraft corporation came up with a series of designs under the division of "Armalite". The intention was to create innovative firearm designs that incorporated many of the new materials being used in aerospace design, such as fibreglass and machined aluminium forgings.

One of Gene Stoner's earlier designs was the AR-10, essentially a larger version of the M16 chambered for 7.62mm NATO. Stoner soon found himself redesigning the AR-10 into a smaller calibre version, the AR-15, chambering the .223 Remington cartridge invented for the US Army's "Small Calibre High Velocity" (SCHV) programme. Gene Stoner told me in 1993 that he much preferred the 7.62mm calibre, however, it is clear the AR-15 is a much easier rifle to control when firing fully-automatically with the smaller .223 round. Following are some pictures of an original Colt AR-15 Model 01, the first AR-15 model made by Colt's after they bought the rights from Fairchild.

Note the green furniture and the "waffle" steel magazine, later magazines are made from aluminium. The following picture shows the right side of the rifle, note the lack of a forward assist. There are other differences that you can pick out. One thing that is notable with this early rifle is that it is made to a much higher standard than later guns, being much more carefully machined.

The following blurry (sorry) picture shows the flash hider and front sight. Note the three-prong flash hider. Later guns would have beefed up prongs, before the adoption of the birdcage suppressor. Note also the machined front sight, made to a much higher standard than the later castings.

The AR-15 was so revolutionary at the time that it was not well-liked by the Ordnance Board who endlessly came up for reasons to reject it. Colt's had bought the design from Armalite, but it took several years to achieve any sizable sales. One of the first buyers was the British Army, where it was issued to the SAS for use in Borneo. Ironically their opponents, the Indonesian Army, were also among the first to use the new rifle.

The US Air Force tried several times to buy the AR-15 to replace their aging M1 carbines, but were not successful until the Kennedy Administration went into full swing in the shape of Robert McNamara. President Kennedy was a life member of the National Rifle Association of America and an ardent gun buff. How much personal involvement he had in encouraging the adoption of the AR-15 by the US Armed Forces is unclear, but Colt's gave him two semi-automatic AR-15s and he wrote them a letter telling them how much he enjoyed shooting the rifles. Robert McNamara was a former executive of the Ford Motor company, and could also see the advantages of the new rifle with its modern method of construction, despite the objections of the Ordnance Board.

To cut a long story short, eventually the AR-15 entered service with the USAF as the M16 rifle. The Army was also forced to buy the rifle, but it was redesigned with a bolt-closure device and called the XM16E1 to indicate it's experimental status. The picture shows the "teardrop" emergency bolt closure device that was also incorporated into the M16A1.

Many problems were encountered with the XM16E1 rifle in Vietnam, most of them due to poor ammunition and a lack of cleaning materials. However, there were other problems such as a prong flash hider that caught on vegetation. This was redesigned into a birdcage type on the M16A1.

After over a hundred small design changes, the US Army and Marine Corps adopted the new rifle as the M16A1 in 1967. The particular rifle shown here is an early one, shipped to Cam Ranh Bay in South Vietnam in early 1968. This particular rifle pre-dates many later design changes, including the trapdoor buttstock. This rifle has the older solid buttplate. It also lacks the chrome-lined barrel found on later M16A1s. The chrome-lining of the chamber was probably the most important change to the rifle in terms of improving reliability. Later on the barrel was completely chrome-lined from the chamber forward, but Colt's had to develop the technique for doing this with such a small calibre barrel first.