By LTC Craig Grosenheider, (USA Retired)
“Gun Trouble” – the December 28th article in The Atlantic claims the current issue M16/M4 is “killing our soldiers” and that the military is denying our infantrymen the “safest and most efficient firearms” available. This point of view is unfortunately relatively commonplace and reflects the implicit assumption that there’s some endless political-industrial conspiracy to ensure US troops never get the good stuff when it comes to small arms.
Bottom line? There are more reliable guns, there are more accurate guns, and there are more powerful guns. But if you accept the tactical school of thought that maintains only hits count, and the first to hit wins – then what the AR15/M16 series enables better than any other is rapid, accurate hits at typical rifle engagement ranges, with capability greatly improved by developments in ammunition, optics and modular accessories over the previous decade.
To claim that the rifle adopted as the M16 in 1962 has changed little in the intervening 52 years is to ignore a nearly non-stop product improvement effort conducted by not only the Army, but the Navy and Marine Corps since then. The M16 series has been in service with the US military longer than any other individual rifle not due to conspiracy, complacence, incompetence or frugality – but because collectively it still represents the state of the art in portable lethality.
The M16/AR15 and its offspring have certainly garnered their share of controversy. Developed as the AR10/AR15 by Eugene Stoner with ArmaLite in the 1950’s, the lightweight rifle was championed by Defense Secretary Robert McNamara and first adopted by the Air Force in 1962 for its security forces. McNamara, and even President John F. Kennedy, soon advocated issuing the rifle to Army of the Republic of Vietnam (ARVN) soldiers and pro-democracy guerilla’s in the early “advisory” phase of the Vietnam War, believing the then current issue M14 was too heavy for the average Vietnamese soldier. US Special Forces advisors fighting alongside the South Vietnamese quickly recognized the advantages of the lightweight, rapid firing and easily controlled 5.56mm AR15 – especially in opposition to AK47 armed North Vietnamese Army and VietCong that could rapidly generate enormous volumes of relatively accurate, long range rifle fire at the individual level.
The Russian AK, and its predecessor the German StG44 “Sturmgewehr” were the earliest widely distributed examples of the “assault rifle” concept, fully automatic rifles firing an intermediate power cartridge from a box magazine. Stoner reasoned he could leverage his experience with aerospace manufacturing to create a lightweight, light recoiling, reliable rifle, and did so with his creation of the AR15 in 1956. Utilizing the by now infamous “direct impingement” gas operating system – incorporated by Stoner deliberately because it added minimal weight to the front of the gun – the AR15 was lightweight but easily controlled in full auto fire, and it’s 5.56mm ammunition earned a fearsome reputation for lethality in early use.
That early wartime success led to a rushed – and catastrophic – fielding to soldiers deploying to Vietnam in 1966, to replace the heavy and hard recoiling M14 then in general issue. Based on the highly regarded WWII era M1, the 7.62mm M14 was accurate and powerful but uncontrollable in full auto fire, capability felt to be critical in confronting an enemy armed with the AK47. The first M16’s were sped to the field with different ammunition, and most importantly gunpowder – than originally specified, which led to increased fouling and extraction problems. Combined with an ill-considered campaign claiming the rifle didn’t require frequent cleaning and resultant dearth of cleaning tools and materials in the field – the results were horrific, as described in The Atlantic article and elsewhere. That experience continues to influence much of the Vietnam generation’s vehement distaste for the “Mattel” gun, and reasonably so.
During and after its disastrous initial fielding, the Army worked hard to correct several issues: type classifying specific ammunition for use with the rifle, chrome lining the chamber and bore to ease extraction and increase reliability, adding a forward assist to aid in chambering – changes that resulted in the M16A1, with a 1:12 twist rate firing 55gr 5.56mm M193 ammunition, fielded to the Army in 1967.
Much of the current controversy can be traced to the Army’s adoption of the M4 Carbine in 1994. With the adoption of the jointly developed M16A2 in 1983, replacing the M16A1, the Army and Marine Corps specified a 62gr, steel core bullet and a 1:7 twist rate heavy barrel in order to improve penetration at long range. The adjustments had the desired effect, but the heavier, faster rotating and thus more stable bullet was somewhat less effective terminally – i.e., punching holes vice destroying tissue. This effect was magnified with the fielding of the M4 with its telescoping buttstock, 14.5in barrel and subsequently reduced velocity. The M16A2, with a 20” barrel, retained sufficient velocity to perform well, but soldiers using the shorter M4 variant encountered failures to incapacitate during engagements in Somalia, and later in Iraq and Afghanistan. The shorter gas system of the M4 also results in a hotter, more abrupt impulse that increases wear on internal parts versus the rifle length gas system. Accordingly, soldiers – mostly special operations forces – using the fully automatic variant of the M4 encountered failures due to overheating, excessive wear and damaged magazines. This also means the M4 requires more attention to both routine and long term maintenance than the M16A2/A4.
So why switch to the M4? For the record, the US Marine Corps chose not to adopt the M4 for general issue, instead electing to stick with the M16A2 and later, the product improved M16A4 – both full length rifles sporting 20” barrels. But, soldiers spend far more time carrying their rifle than shooting it, and the troop-level clamor in the Army for the lighter, “sexier” carbine length M4 was sufficiently loud to offset any argument that the heavier M16A2 was more effective. There are compelling arguments in favor of smaller, lighter and more compact weapons especially when carrying and using them inside structures, vehicles or aircraft.
Operations in Iraq and Afghanistan beginning in 2003 further exposed widespread difficulties with the M4 and its issued M855 ammunition. For the first time, a majority of direct combatants were armed with the carbine instead of the M16A2, and the shorter gun proved both less reliable and less lethal. These issues attracted considerable attention – over time resulting in an extended series of M4 reliability upgrades including an improved magazine, heavier buffer and barrel assembly to slow cyclic rate and improve heat dissipation. In 2013, the Army announced it was recapitalizing all of the M4’s in the Army inventory to M4A1 configuration, incorporating both the reliability improvements and the full auto selector switch from the SOCOM variant.
Combat experience in Iraq and Afghanistan also directed effort towards improving the cold war era M855 ammunition issued when the conflict started. As noted earlier, the 62gr projectile designed for the M16A2 was developed for medium to long range penetration, and did not perform well in the short barreled carbine. A variety of approaches were attempted to enhance 5.56mm lethality out of the 14.5” M4, eventually resulting in the very successful 77gr Mk262, 62gr Mk318 “Special Operations Science and Technology” (SOST) projectiles, and the improved general issue lead-free M855A1 ammo introduced in 2013 – all providing a significant increase in terminal performance and accuracy from the M4 compared to the earlier ammo.
The US Special Operations Command (USSOCOM) Special Operations Peculiar Modification (SOPMOD) program, initiated by the Navy in the late 80’s to develop an interchangeable, modular accessories system, is a key aspect of the rifles development and shares much of the credit for its longevity as an individual weapon. Transforming the one size fits all M16A4/M4 into a “system of systems”, the SOPMOD and associated Army Modular Weapons System (MWS) innovations turned the rifle into an infinitely customizable weapon with the introduction of a wide and continually increasing variety of accessories – telescopic and red dot optical sights, infrared and visible lights, bipods and sling mounts, foregrips, suppressors and more – all designed to improve manipulation, reduce firing signature and increase hit probability throughout a broader range of combat conditions.
What makes the evolved M16/AR15 series so effective that the Army’s Individual Carbine competition conducted in 2013 – evaluating 8 other competing designs under demanding conditions – concluded there was nothing to gain by replacing it? In addition to the 2013 evaluation, the M16 series has outlasted a nearly non-stop campaign to replace it with “leap ahead” rifle technology, from the flechette based Special Purpose Individual Weapon (SPIW) program in the 1960’s, to the Objective Individual Combat Weapon (OICW/XM8) program, effectively terminated in 2005, and has even survived the 2009 limited adoption of the Mk16/Mk17 Selective Combat Assault Rifle (SCAR), a purpose built modular weapons system painstakingly designed in full cooperation with downrange “operators” to specifically address requirements of USSOCOM. SOCOM fielded the 7.62mm SCAR-H / Mk17, but declined to adopt the 5.56mm variant because in their opinion it did not represent a significant improvement over the current M4A1 Carbine. Despite the option to use nearly any weapon they choose, when a SOCOM operator arrives on the objective today he’s more than likely carrying a 5.56mm M4 variant.
The AR15/M16/M4 has become and remained wildly successful as a tactical rifle because it performs it’s task exceedingly well – combining manageable recoil, accuracy, lethality and reliability with compact size and weight and near perfect “ease of use” manipulation and ergonomics to a higher degree than any of its competitors.
Perhaps most compelling is that this product improvement effort has spawned what is today the most successful “civilian” law enforcement and self defense rifle in history – dominating tactical rifle competition from Camp Perry to 3Gun/Multi-Gun, law enforcement and household self defense so completely that you’d be forgiven if you thought the AR15 was the only lightweight semiautomatic “tactical” rifle available.
That is most definitely not the case – but for a variety of very good reasons, Stoner’s design has come to define the tactical “black rifle” to a degree not even the vaunted AK can claim. To maintain that the same gun that has achieved such an exceptional level of foreign military sales, license production and commercial success is somehow a poor or even substandard choice as a US military rifle is a very difficult argument to sustain.
Inevitably, the M16 era will come to a close, but the fact that it’s been around this long is hardly surprising or difficult to understand to the vast majority of military personnel and civilians that have relied upon it for decades.
- LTC Craig Grosenheider, (USA Retired) is a defense consultant in Colorado Springs CO