There are still a lot of M16A2s in theater. They are made by Colt and FN. FN has the current contract for the M16A2 and A4.
The A4 is the flattop version of the A2, most often found with the M5 RAS (rail adapter system).
In an Army Infantry platoon you will have three rifle squads. Each squad has 9 men, They are armed as follows. 2 M249 SAWs, 2 M203 grenade launchers and 5 M16s (A2s or A4s) or M4s (depending on what the unit is issued. You also have a platoon HQ with a platoon leader, platoon sergeant, medic (attached from the HHC medical platoon), RTO (radio telephone operator) FIST (Fire Support Integration Team member, attached from the Direct Support Artillery Battalion). Two machingunners, 2 assistant machine gunners, 2 ammunition bearers. The machine gunners, assistant gunners and medic get M9 pistols. Everyone else has whichever rifle the rest of the unit gets. You also have an antiarmor section composed of two javelin gunners . They also have rifles. This organization or one similar will be folowed in light units, such as the 10th Mountain Division, 101st Airborne (Air Assault), 82d Airborne.
A mechanized platoon will be organized differently. They will break down into a vehicle team, driver, gunner and Bradley commander and a 6 man dismount team. The vehicle crew has rifles, the dismount team has an M203, an M249 and 4 rifles.
All soldiers assigned to a tank crew have M9 pistols. Each tank has 2 M4s that are issued with the tank for crewmen to use while dismounted. That is why you may have heard reports of American soldiers using captured AKMs. When they started putting the men in the armored units on foot and HMMWV patrol, there weren't enough rifles to go around. (only two per tank) so the local commander supplemented his M4s with captured AKMs.
HTH
Jeff
