Lance Cpl. Leobardo Nunez, an infantry automatic rifleman with Weapons Platoon, Alpha Company, 1st Light Armored Reconnaissance Battalion, provides security during a patrol in Afghanistan in March. An expert says the Infantry Automatic Rifle, which has replaced the Squad Automatic Weapon, could also replace the MK12 Special Purpose Rifle for designated marksmen, saving the Marine Corps money. (Cpl. Alfred V. Lopez / Marine Corps)
Thousands of the Corps' new automatic rifles, designed to replace the decades-old, belt-fed M249 Squad Automatic Weapon, are now in the hands of deploying Marines. But one expert — a gunner deployed to Helmand province, Afghanistan — says the highly accurate M27 Infantry Automatic Rifle should replace some of the Corps' other precision weapons.
The accuracy and increased reliability of the IAR make it well suited for more than just suppressive fire, said Chief Warrant Officer 2 Chris Jones, who is deployed with 2nd Battalion, 7th Marines, out of Twentynine Palms, Calif.
"This weapon platform could be used as a multipurpose weapon system in the infantry squad, using [it] as an automatic rifle and as a designated marksman rifle," Jones said in a Marine Corps news release.
Weighing about 9 pounds, the IAR is capable of firing single long-range shots with deadly accuracy. However, unlike standard service rifles, it also can be fired fully automatic. There is one IAR in virtually every four-man fire team, with three per squad.
After seeing it in action, Jones is convinced that the IAR is more than capable of filling the role of the MK12 Designated Marksman Rifle, which is essentially a beefed-up M16 with a precision upper receiver, barrel and scope.
The MK12 can reach out and engage targets with well-placed precision fire at distances of 700 meters or more. That allows an infantryman to neutralize targets that pose a threat to the unit but are beyond the effective range of most Marines' rifles. Because the IAR comes with reliable precision components out of the box, and standard optics can easily be swapped for more powerful ones on its rail system, Jones argues it is capable of accomplishing the same feats as the MK12.
"In a time of fiscal restraints, one rifle potentially serving two purposes would be huge," Jones said.
And because the IAR is ergonomically so similar to the MK12 and the standard issue M16A4, it requires little, if any, training for any Marine to pick one up and begin dropping targets at distance.
Jones told Marine Corps Times that he has conducted his own live-fire exercises comparing the IAR to the SAW, MK12, M16A4 and M4 Modular Weapons System, using a handful of cartridges that included standard 5.56mm ball, tracer and MK318 Special Operations Science and Technology rounds. In all cases, the IAR outperformed the other weapons at 100 meters, he said. The IAR consistently grouped shots inside about 1 to 2 inches.
"The end state is that the M27 IAR is consistently the most accurate direct-fire, small-arms weapon system organic to the infantry rifle squad," Jones said.
That could make it a solid replacement for the MK12, which, like the IAR, uses 5.56mm ammunition.
The MK12 is not to be confused with the Marine Corps' defunct Designated Marksman Rifle based on the M14 platform. That rifle fired heavier 7.62mm rounds.
The IAR was introduced as a lighter weapon, which Marine leadership said would help units maneuver more quickly and conserve ammunition. The rifle is less than half the weight of the SAW and uses standard 30-round magazines rather than large 200 round drums. What is more, the IAR is similar in size and function to the M16, so, unlike the SAW, it can be used for room clearing. Whereas SAW gunners had to remain behind in a supportive role when a stack of Marines cleared a building, IAR gunners can stay in the stack and help clear areas faster, according to Marine Corps Combat Development Command officials. Jones agrees.
A Marine with an IAR can quickly shift between functioning as an automatic rifleman, a rifleman and a designated marksman, he said. The IAR allows a Marine to "to switch from precision single shots, to semi-automatic, to controlled fully automatic bursts as he maneuvers and the enemy situation changes."
That means the IAR can not only replace the SAW but also stand in for an M16 and the MK12.
In addition to its increased capabilities, the IAR has also proved more reliable.
While traditional M16 and M4 platforms — including the MK12 — use what is called "direct gas impingement" to cycle the weapon, the IAR uses a "gas piston system." When an M16 or M4 is fired, the rifle bleeds a small portion of the expanding gases, which propel a bullet down the barrel, into a gas tube that runs the length of the barrel. The gases travel down the tube to the bolt carrier. There, the expanding gases exert enough force to drive the bolt back, extracting the spent casing and chambering a new cartridge. The downside to the system is that those gases are hot, dirty and carry carbon, which can foul the bolt carrier group or overheat the rifle and cause a malfunction.
In the IAR's gas piston system, however, gases bled from the barrel only travel a short distance before hitting a piston that travels the length of the barrel and directly strikes the bolt carrier to cycle the rifle. This prevents dirty gases from ever reaching the intricate inner workings of the rifle, keeping them clean, cool and moving freely.
But the real proof of the rifle's versatility, Jones said, is that it is performing amazing feats in combat.
In one case, a Marine with an IAR was able to maneuver into position under fire and silence an enemy machine-gunner at 500 meters by hitting him through a loophole with a single round, Jones said. The same kill with a SAW, even if possible, would have required much more ammunition.
That precision makes the IAR a capable arm when compared to either the SAW or the MK12.
"The weapon system, as is, has already demonstrated it is capable of fulfilling this dual-purpose role," Jones said. "It is up to the Marine Corps to now designate this as a relevant task for the Marine and his M27, and then pursue this via training and education."