The Marine Corps is contemplating taking away carbines from infantrymen and replacing them with a highly accurate German-designed rifle originally meant to give squads accurate suppressive fire. Rather than a specialized weapon, the M27 Infantry Automatic Rifle (IAR) could soon be issued to all frontline grunts.
The M27 is built by German arms maker Heckler and Koch and is based off their HK416 rifle. The M27 IAR is touted as a more reliable, more accurate platform capable of achieving the same suppressive results as the older M249 squad automatic weapon with fewer bullets. Outwardly similar to the the Marine Corps' M4 carbines and M16A4 rifles, the M27 uses a gas-operated piston system that runs cleaner than the direct impingement systems powering other small arms. The direct impingement system, while reliable, also injects gunpowder residue directly into the weapon's innards. The M27's gas piston system cycles residue outside the rifle, resulting in a weapon that needs less frequent cleaning.
The key to achieving the same suppressive effect with less bullets is increased accuracy. The M27 uses a (ACOG), a 3.5x magnified rifle scope with a red dot sight mounted above it. The rifle also utilizes a free float barrel system: as rifle barrels heat up from use, they become more susceptible to deviations from handling objects touching them, such as the handguard. The free float system ensures the barrel is untouched from the upper receiver to the muzzle.
The Marines first started using the M27 IAR in 2010, buying 4,000 M27s to replace the . The M249 uses the same ammo as and but has a high rate of automatic fire—up to 800 rounds a minute—to provide suppressive fire during infantry combat. However the M249 is also less accurate, less reliable, and much heavier than other Marine small arms. The M249 is well suited to pouring a wall of lead downrange, which runs counter to the Marines' concept of individual marksmanship. Three M249s were issued to every marine rifle squad of 13 Marines.
The Marines are so happy with the M27 that they'd like to put them in the hands of the entire rifle squad, something that would require purchasing an additional 11,000 rifles. Each M27 costs $3,000, plus another $2,000 for the ACOG optic and other accessories, such as bipods and , for a total of $5,000 per weapon. Eleven thousand rifles would cost $55 million dollars. That's not a lot of money considering a single F-35B Joint Strike Fighter, of which the Marines plan to purchase 353, .
Arguably, the M4 is "good enough" and the Marines' tactical airpower is older and in more dire need of replacement shape than their small arms inventory. After all, the Army likes their M4 carbines just fine. That said, infantry combat is the bread and butter of the Marine Corps. The Marines have a decision to make, and it won't be an easy one.