M27 Infantry Automatic Rifle

The M27 Infantry Automatic Rifle (IAR) is a 5.56mm, select-fire assault rifle / squad automatic weapon developed from the HK416 by Heckler & Koch. It is used by the United States Marine Corps (USMC) and was originally intended for automatic riflemen, but is now issued to all infantry riflemen as a replacement for the M16A4 and the M4A1. The USMC initially planned to purchase 6,500 M27s to replace a portion of the M249 light machine guns employed by automatic riflemen within Infantry and Light Armored Reconnaissance Battalions. Approximately 8,000–10,000 M249s will remain in service with the Marine Corps to be used at the discretion of company commanders. In December 2017, the Marine Corps announced that it would equip every member of an infantry squad with the M27, supplanting the M4 carbine which would be retained at the platoon leadership positions and above. A further subvariant, the M38 DMR was created as a designated marksman rifle, retaining most features of the M27.

Background

In 1999, a Universal Need Statement was issued for an IAR. Around 2000, the 1st Marine Division's 2nd Battalion, 7th Marines Regiment conducted initial, limited IAR trials which confirmed the desirability of a light automatic rifle. The key difference between a lighter infantry rifle and a more heavily built automatic rifle is the ability of the latter to maintain sustained continuous fire without stoppages, overheating, or loss of accuracy. Experiences in Iraq and Afghanistan resulted in formal requests for recommendations. The Universal Need Statement spent six years going through the procurement process before an official program was begun and a list of required capabilities was created in early 2005.