This variant of the M16A2 rifle comes with the M203 underbarrel 40mm grenade launcher attached. The addition of the M203 raises the weight of the weapon from 2.52 kg unloaded to approximately 5.48 kg. The M203 is a single shot, breech loading weapon. The M203 has a maximum range of approximately 400 meters. During combat, the recommended minimum safe range for firing the grenades is 31 meters.
The M16A2 5.56mm rifle is a lightweight, air-cooled, gas-operated, magazine-fed, shoulder- or hip-fired weapon designed for either automatic fire (3-round bursts) or semiautomatic fire (single shot) through the use of a selector lever. The weapon has a fully adjustable rear sight. The bottom of the trigger guard opens to provide access to the trigger while wearing winter mittens. The upper receiver/barrel assembly has a fully adjustable rear sight and a compensator which helps keep the muzzle down during firing. The steel bolt group and barrel extension are designed with locking lugs which lock the bolt group to the barrel extension allowing the rifle to have a lightweight aluminum receiver. The M16A2 is capable of firing all NATO standard 5.56mm ammunition and can fire 40mm grenades when equipped with the M203 Grenade Launcher.
- In Ghost Recon, it is misidentified as an M16A2 even though it's an M16A4 denoted by its flat top upper receiver. However, in Ghost Recon 2 it is named simply "M16".
- In Ghost Recon it is the Riflemen's primary with an optional M203 grenade launcher, but in Ghost Recon 2 the grenade launcher is permanently attached.
- In the PS2 version of Ghost Recon 2, it is incorrectly depicted as fully automatic, but in the Xbox version it is correctly restricted to 3-round burst.