The M16A4 is an assault rifle that fires 5.56mm NATO ammunition, it is also the successor to the M16A2 and M16A3. It is currently used by the United States Marine Corps and some US army units. It looks very similar to the M16A2 but has several useful features like a removable carry handle and integrated rail mounting system.
In GameEditIn Armed Assault the M16A4 is used only by US soldiers, it uses the 30 round and 20 round STANAG magazines and has two different fire modes, a three round burst mode and a semi-automatic mode. It still has the same restrictive sights as the M16A2 but is slightly less accurate when using the burst mode so it is recommended to stay on semi-automatic.
There are four different versions of the M16A4 in Armed Assault, the first version is a standard one with iron sights, the second replaces the iron sights with an M150 RCO ACOG sight. The third version mounts a M203 grenade launcher. The fourth is a M16A4 which has the M150 RCO sight mounted and also has an M203.