Commandant Gen. James T. Conway gave Corps officials the green light in April to issue approximately 450 M27 Infantry Automatic Rifles, enough to replace every M249 squad automatic weapon in four infantry battalions and one light armored reconnaissance battalion.

The limited fielding is a final test to find out if the Heckler & Koch-made weapon performs as well in an operational environment as it has in testing, said Charles Clark III, who oversees infantry weapons requirements at the Corps’ Combat Development and Integration office at Quantico, Va.

“The battlefield test will be a verification of what we have already established through extensive operational testing,” Clark said. “We want to get a user assessment prior to full-rate production.”

Conway’s decision comes despite his past concerns about replacing the M249 with a magazine-fed automatic rifle. His main worry is whether the M27’s light weight and accuracy will be enough to make up for the loss of suppressive firepower Marine gunners will give up when they go into battle without the belt-fed M249.

Program officials acknowledge that a 30-round magazine cannot produce the high volume of fire the M249 is capable of when loaded with a 200-round belt. The Corps is considering high-capacity magazines that can hold 50 or 100 rounds of 5.56mm ammo, but Marines that deploy with this first batch of IARs will carry only 30-round magazines.

“The initial limited fielding will not include a high-capacity ammunition source, but that remains an option,” Clark said, explaining that such magazines will have to undergo a separate round of testing.

The M27, a variant of the H&K 416, weighs just 7.9 pounds, unloaded. By comparison, the M249 weighs 17 pounds, unloaded.

Marines involved in operational testing at Twentynine Palms, Calif.; Fort McCoy, Wis.; and Camp Shelby, Miss., were “very comfortable with it because it’s a lot like a M16A4 and it’s far more maneuverable and portable” than the M249, Clark said. “The H&K gun has performed very well throughout operational testing.”

Marine officials selected the H&K weapon in October over two prototypes from Colt Defense LLC and one made by FN Herstal. (Colt makes the M4 and FN makes the M249.) The M27 uses a short-stroke gas piston, which proved more reliable than the M16/M4’s direct gas system in an Army dust test in late 2007.

The new IAR, which fires from the closed-bolt position, is most effective when employed as a point-target weapon, program officials maintain.
“The accuracy has been a real standout,” Clark said. “The IAR has demonstrated to be a far more accurate gun” than the M249, which fires from the open-bolt position.

In the defensive role, the M27 used “far less” ammunition to drop the same number of targets compared to the M249, Clark said.

Source: Matthew Cox for

Up Next

Philippine Coast Guard and U.S. Navy make coastal areas safer.

Commandant Gen. James T. Conway gave Corps officials the green light in April to…