Marines swap firepower for accuracy with IAR
For at least a decade, factions of the Marine Corps have pushed for replacement of the legendary 5.56mm M249 Squad Automatic Weapon in infantry fire teams.
Weighing more than 22 pounds with a 200-round drum, the belt-fed light machine gun slows down Marines while patrolling and maneuvering under fire, critics said. It isn't accurate, it's temperamental and takes too long to get working after jams, they added.
Beginning this year, the critics will get their way.
Commandant Gen. Jim Amos has approved the full fielding of the M27 Infantry Automatic Rifle, a sleek, 5.56mm weapon that will become the new standard for automatic riflemen. There will be one IAR in virtually every four-man fire team, with three per squad, 28 per company and almost 4,476 across the Corps.
"After a rigorous testing process, both in garrison and deployed environments, and in-depth consultation with weapons experts through the Corps, the commandant approved the fielding of the M27 Infantry Automatic Rifle," said Maj. Joseph Plenzler, a spokesman for Amos. "The fielding of the IAR will significantly enhance the ability of our infantrymen to gain and maintain fire superiority, reduce their fighting load and provide them a more ergonomic and accurate weapons system that can keep up during the assault."
It's a controversial change for the Corps that will affect tactics, techniques, procedures and training. Marine fire teams have been built around a 0311 infantry rifleman carrying a SAW since the 1980s, when the U.S. military adopted it to add automatic firepower to small units. Nine SAWs will be kept in each rifle company, but they'll largely be in reserve, and used at commander's discretion.
Widespread fielding of the new rifle is expected to begin next summer, said Lt. Col. Mark Brinkman, head of the infantry weapons program at Marine Corps Systems Command, out of Quantico, Va. However, five units already were issued the weapon late last year as part of an experimental fielding, and one unit, 1st Battalion, 3rd Marines, has it downrange.
The IAR is a variant of Heckler and Koch's HK416 assault rifle, which is popular with special operators and frequently used with suppressors. It weighs 9.2 pounds loaded, less than half the weight of SAW, made by FN Herstal. It has an adjustable butt stock and runs on standard 30-round magazines, although the Corps also is exploring the possibility of a high-capacity magazine that would carry between 50 and 100 rounds.
In part because there is no quick-change barrel like the SAWs, the IAR has a sustained rate of 40 rounds per minute for 600 rounds, or 28 rounds per minute when the temperature is more than 100 degrees. That's far less than the SAW's sustained 85 rounds per minute, but program officials said the IAR offers more than enough benefits to make up for the lower rate of fire.
Why it was chosen
Chief among the advantages are increased accuracy and the ability for small units to move more quickly and in tandem, said Charles Clark III, head of infantry weapon requirements at Marine Corps Combat Development Command, out of Quantico.
The IAR has a 16.5-inch free-floating barrel, immediately making it one of the most accurate weapons carried by a squad of Marines. Common on sniper rifles, the free-floating barrel attaches to the rifle only at the receiver, keeping the weapon's zeroing truer, even when placed under the weight of optics, pointers and other gear. Marksmanship officials recommended this year that the free-floating barrel be adopted on standard service rifles, but it hasn't been done yet.
Each auto-rifle will be paired with Trijicon's SAW Day Optic. It has 3½-times magnification and slightly longer eye relief than the 1½ inches a Marine typically keeps between his shooting eye and Trijicon's Rifle Combat Optic, providing Marines carrying the IAR with protection from the weapon's larger recoil when used on full auto.
The lightweight design of the IAR also will allow automatic riflemen to stay in a stack of Marines as they clear buildings in an urban area, rather than staying behind in supporting positions, Clark said. Consequently, he said, Marine squads should be able to move more quickly through buildings, with three extra Marines — one per fire team — in a stack.
Maintenance on the IAR also will be easier, considering it has a gas-piston system that prevents combustion gases and dust from entering the weapon's interior. Also, in the amount of time it takes to clear the typical jam on a SAW, a Marine can clear a jam on the IAR and fire another 30-round magazine, Marine officials said.
Gen. James Conway, who called for the experimental fielding last year before retiring, questioned the wisdom of replacing the SAW's ability to put hundreds of rounds downrange quickly, with an automatic rifle using 30-round magazines.
Even though 1/3 is the only unit deployed with the IAR, Marine officials decided they had seen enough to approve full fielding. The decision, approved May 23 by Amos, was reached after collecting positive feedback from grunts, weapons maintainers and the heads of units that had completed Enhanced Mojave Viper training at Twentynine Palms, Calif., Clark said. It also was recommended by the Infantry Operational Advisory Group, a panel comprising regimental commanders from across the Corps.
A long-running debate
Lance Cpl. Alonzo Middleton, who is deployed to Helmand province, Afghanistan, has been carrying the SAW for three years.
"That's why I have to work out all the time so I can lift it," said the infantryman from Bravo Company, 1st Battalion, 23rd Marines.
The weight aside, he said, "it's my best friend. I'd rather have more firepower."
He's never fired the IAR, but he spotted one in the chow hall at Camp Dwyer and asked the Marine carrying it, a member of 1/3, if he could hold it.
"It felt like a toy compared to this," he said pointing to his SAW.
He said he wouldn't mind trying it out, though, because at the end of the day, the SAW is a monster of a machine gun to carry around.
"I tried to turn a corner with this thing once while we were clearing a building during training and I ran into a wall," Middleton said.
Adoption of the IAR is unlikely to tame all critics.
Marines argued the pros and cons of the option for years, as the proposal slowly made its way through the Corps' chain of command.
Marine officials said it stretches back to at least August 2001, before the 9/11 attacks and the wars in Iraq and Afghanistan. Tired of lugging around the SAW, grunts with 2nd Battalion, 7th Marines, out of Twentynine Palms, purchased three commercial automatic rifle variants and pitted them against the SAW. They recommended that the Corps pursue an automatic rifle, citing its advantages of accuracy and employment speed.
A month later, the idea was brought before the Marine Corps Ground Board, a panel that includes the four Marine division commanders and the deputy commandant for plans, policies and operations. The board recommended in September 2001 that the Corps pursue the use of a new automatic rifle.
The SAW played a prominent role in the wars in Iraq and Afghanistan, but Marines overseeing acquisitions and weapons requirements continued to move toward fielding a weapon that could replace it. The competition took a major step in December with the naming of four finalists, and vaulted back into the spotlight.
Conway, an infantry officer, raised concerns about the proposal multiple times, publicly and privately, Marine officials said.
In 2010, he gave approval for the Corps to field 458 rifles to the five units taking it to war this year, but said SAW offered a lot of advantages.
"Let's talk about suppression and the psychology of a small-unit fight, that says that the other guy's got a light machine gun and I've got an automatic rifle," he said. "I'm going to be hard-pressed to get fire superiority over him, you know, to keep his head down instead of him keeping mine down, because that 200-round magazine just keeps giving."
IAR-prompted changes
Already, the IAR has triggered a debate over marksmanship training and what a unit can take to war.
In one example, Marine officials at the 2011 Combat Marksmanship Symposium recommended the IAR be banned from rifle qualifications, even for the automatic riflemen who take it downrange. While there was some dissent, marksmanship officials ultimately recommended to make all Marines qualify with either the M4 carbine or M16A4 rifle, negating an advantage the IAR's free-floating barrel may have offered.
Adoption of the IAR also has led Marine units to collect modern polymer magazines from Marines, to prevent them from taking the popular "PMAGs" downrange. Polymer magazines won't insert all the way into an IAR, potentially creating problems for Marines who toss ammo to one another during a firefight, two Marine gunners said.
Individual units are still allowed to order PMAGs and other 5.56mm ammo once they receive budgets 180 days before deployments. But because only standard-issue magazines are authorized with the IAR, Marine commanders are deciding that PMAGs aren't worth the hassle.
"There's an extra piece of plastic in the way," one Marine gunner said of the PMAGs. "It works just fine in the M16A4, but not in the IAR."
Standard-issue magazines, rolled out by the Army in 2009 and 2010, will likely be used instead. Identifiable by their tan follower, they have better reliability and fewer stoppages than older standard-issue magazines, which have green and black followers. Some green followers are still in the operating forces, but service members are urged to turn in black follower magazines, the oldest of the three, to their units.