Considered the ultimate M-16 incarnation. the A5 model of the M16 was the last genration M-16 to be produced; Equipping the Osean Army, Marines, UPEO Special Forces, and North Point Federal Police, Also used exclusively by Windhover-1.
The rifle was first produced in 2022 and equipped over half of Osea's military by 2025. The new rifle as the ICR title suggested was adjustable to operator liking, a soldier with the turn of an allen wrench could switch barrels, caliber, stocks, and accessories such as the M-203 grenade launcher and ACOG scope. Calibers for the M-16A5 included 5.56x45mm NATO, 7.62x51mm NATO, 6.5mm Grendel and possibly a caseless round could be developed for the weapon.
The Rifle saw action in the Corporate War with UPEO Special Forces and saw continued use in the 2048 conflict following the Corporate War. Rein uses one of these at the target range when she is not on mission, Dimitri also unloaded a crate of these rifles while helping his father at hangar C-1. The base guards use the M-4A2 I.C.W.S (Individual Combat Weapons System) variant of the rifle, essentially an M16 carbine. Windhover-1 also uses the M-16A5 while not piloting his signature F-16C Fighting Falcon.