U.S. Marines with 3rd Battalion 8th Marine Regiment fire the M27 Infantry Automatic Rifle during a live-fire weapons exercise at range F-18 on Camp Lejeune, N.C., Dec. 8, 2017

M27 Infantry Automatic Rifle

Marine Corps Systems Command is purchasing M27 Infantry Automatic Rifles from a single source vendor based on feedback from Marines. Here's how it stacks up against the M4