The Evolution of the M16 Rifle

M16 Rifle

One of the most venerable rifles in the world, the M16 has served American forces faithfully from the jungles of South America to the deserts of the Middle East. In service for nearly half a century, theM16 was at its inception a departure from traditional battle rifle thinking, and a markedly differed weapon than those being produced by America’s adversaries. Hello and welcome to another episode of The Infographics Show, today we’re taking a look at the evolution of one of the most iconic rifles in history, the M16. Following World War II the US Army had a serious problem. Its infantry was being equipped with up to four different weapons, from the M1 Garand to the Thompson sub machine gun, and all were proving ineffective in modern combat. What the army desired was a single weapon that could do the job of the various different weapons infantry units may be equipped with, something that could be lethally accurate at long ranges such as the M2 Carbine, while being able to deliver suppressing fire like the Browning Automatic Rifle.

The Army decided that it would need a rifle chambered to fire the 7.62 mm round, which would also be used by the new general-purpose machine gun under development. Various designs were submitted by well known manufacturers, to include upgraded designs of the M1 Garand, but entering the competition late,  Arma Lite was forced to hurriedly submit an AR-10 prototype rifle for testing. Unlike other rifles which featured walnut and steel, the AR-10 was a surprisingly lightweight design made of aluminum and plastic, weighing in at only 6.85 lbs while empty. Though Springfield Armory test staff commented that the AR-10 was the best automatic rifle they had ever tested, the Army ended up choosing what would become the M14 rifle, which was basically just an updated M1 Garand with a20-round magazine and automatic fire capability.

A few years later the M14 would come face to face with the AK-47 in the jungles of Vietnam. Almost immediately battlefield reports claimed that the M14 was completely uncontrollable when firing in full automatic mode and that soldiers couldn’t carry enough ammunition to maintain fire superiority over the AK. In fact many soldiers had taken to ditching their M14s for AK-47s pulled off the corpses of slain enemy combatants, which led to friendly fire incidents when American troops fired on the sound of an AK-47 in their midst believing it to be an enemy. The US was being out gunned daily in the dangerous jungles of Vietnam, and it was clear that a replacement rifle had to be found and asap. The Army was thus forced to reconsider a 1957request by General Willard G Wyman, commander of the US Continental Army Command, to develop a lighter.223 caliber, 5.56mm rifle which could fire in both semi and fully automatic modes. With most believing that the.223 caliber round lacked the killing power of a.30 caliber round, the new rifle would have to prove that it could penetrate a US helmet at 500 yards (460 meters) and retain a velocity in excess of the speed of sound, while still being able to match or exceed the wounding ability of a.30 caliber round.

In response, Arma Lite scaled down their AR10prototype and developed the AR-15.Firing the smaller.22 caliber round, the bullets would destabilize when entering the human body, and fragment or tumble, thus vastly increasing their lethality over a.30 caliber round which might zip straight through. The smaller caliber also meant that the rifle would be much more controllable in fully automatic firing mode due to the vastly reduced kick, and with rounds being a third the weight of.30 caliber rounds, soldiers could carry more ammunition and sustain fire for longer. The AR-15 could also fire at rates of 600-700rounds a minute with an impressively low jamming rate, and the individual parts of the rifle were stamped out instead of being hand-machined, allowing them to be mass produced and greatly reducing both their cost and increasing the speed of manufacturing.

The lack of specialized equipment needed for its construction also meant that unlike the AK-47, who’s manufacture was limited to a few plants with the proper equipment, the M16 could be produced nearly anywhere, which would make interruption of supplies in case of war against a foe such as the Soviet Union nearly impossible. Despite the obvious superiority of the AR-15over the M-14, the Army was very reluctant to adopt the rifle. In fact it was the Air Force who was the first to adopt the weapon, ordering 8,500 rifles and 8.5 million rounds of ammunition.

The Pentagon’s Defense Advanced Research Projects Agency then acquired 1,000 of the Air Force’s AR-15’s and shipped them to be tested by the South Vietnamese Army, with the Vietnamese soldiers quickly falling in love with the weapon. Over the course of testing by the South Vietnamese, the AR-15 recorded zero broken parts while firing 80,000 rounds in one stage of testing, and in total they needed only two replacement parts for the 1,000 weapons over the entire course of testing. The Vietnamese government would go on to request that the US provide the AR-15 as the standard rifle for its forces, but the request would be denied by Admiral Harry Felt, commander in chief of pacific forces, on recommendation of the US Army. Historically a hard-headed service, the US Army continued to decline the AR-15 despite it’s growing and very obvious superiority. During 1962 and 1963 the US military continued to test the weapon with positive evaluations emphasizing its lightness, lethality, and reliability.

The Army Material Command however criticized the weapon’s inaccuracy and penetration power at very long ranges, however in 1963 American special forces asked for the AR-15 to be made their standard weapon. CIA operatives and select Army Airborne units were also being equipped exclusively with the AR-15, and eventually Secretary of the Army Cyrus Vance ordered an investigation into why exactly the AR-15 was being rejected by the Army. The investigation revealed that the personnel in charge of testing the AR-15 up against the M14 had rigged the tests in favor of theM14. Within the Army Material Command the bias remained, as it had historically been, with larger caliber rifles capable of firing at longer ranges, believing that slow, deliberate fire and a round that could remain accurate at extreme ranges was of utmost importance.

Yet in the jungles of Vietnam where fire fights took place at ranges of thirty to fifty yards, the ability to deliver automatic fire quickly was critical, and the M14 was poorly suited for the job. It would take an order directly from Secretary of Defense Robert McNamara to halt production of the M14, and for US armed forces to formally adopt the AR-15 as their main battle rifle. Yet the Army was allowed to ask for modifications for its AR-15s, which by now should have proven to be a mistake because you should never let the Army ask for anything. With delivery of the first shipments of AR15s,Army staff asked that the design be changed to include a manual bolt closure, so that a soldier could ram a round in if it failed to seat properly in the chamber.

The Air Force immediately objected over this request, stating that during three years of testing and operation under all types of conditions, the Air Force had no record of malfunctions that could have been corrected by a manual bolt closing device. They further stated that the addition of a manual bolt closure feature would add weight and complexity to the weapon, reducing its reliability. The Marine Corps would come to the Air Force’s defense, stating that there was absolutely no need for the added feature. In the end, Colonel Howard Yount, who managed Army procurement of the rifle, would defend the request by stating, “the M-1, the M-14,and the carbine had always had something for the soldier to push on; that maybe this would be a comforting feeling to him. or something.

” Needless to say, Air Force and Marine Corps personnel would roll their eyes at the good Colonel, though unfortunately the Army’s insistence would go on to force a redesign of the weapon anyways, resulting in the M-16. The first version of the M16 however would fare poorly in wet conditions such as those of the Vietnam jungles. It experienced a malfunction rate of two per1,000 rounds fired, and soldiers began writing letters home about the terrible quality of their new rifles. Eventually enough letters from soldiers overseas were forwarded by concerned parents to congressmen that a Congressional investigation was launched.

That investigation would discover that theM16 had been billed as self-cleaning, despite the fact that no rifle is or has ever been. Thus troops were issued the rifle without cleaning kits or instructions on how to properly clean the weapon. Because the M16 works by redirecting part of the high pressure gases caused by firing back towards the bolt and thus chambering and seating a new round, the rifle was specially vulnerable to misfiring or jamming if not cleaned regularly. The investigation also found that the M16and 5.

56 round it fired had been approved for use with DuPont IMR8208M extruded gunpowder, but in production the powder had been switched to WC846 ball powder which produced much more fouling and thus jammed the M16 much more frequently. The lack of a forward assist also made it impossible for a soldier to successfully seat a round when the rifle jammed, and lastly the firing chamber was not chrome-plated, which created corrosion problems. By 1968 though these issues had been addressed and corrected, in the form of the M16A1, and a report by the Department of the Army found that the new and improved rifle had found widespread acceptance by US troops.

By the end of the war in Vietnam, a Blue Ribbon Defense Panel concluded that the M16 had saved the lives of 20,000 US servicemen during the war, who would have died had the M14 remained in service. The M16 would go on to continue serving US armed forces all the way up to the wars in Iraq and Afghanistan, where it served alongside its slightly smaller and more maneuverable cousin, the M4.

Combat troops would go on to continue praising the reliability of the M16, with one unit in the Helmand province of Afghanistan reported that despite being covered in fine powdered sand, being dusty, wet, and covered in mud, the weapons would not jam even during intense, hours long firefights. Only a single soldier reported his weapon jamming, and only after his M16 was covered in mud after climbing out of a canal. After clearing the weapon, the rifle continued firing and remained operational for the rest of the engagement. Still receiving high marks for reliability, accuracy, lethality, and range, the M16 is slowly being phased out across the US military in favor of the M4, yet it still remains one of the best battle rifles ever created.


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