In Battlefield Heroes, the M16 was released as part of the Battlefield Heroes Gets Bad Company event. Its stats in the Battlefield Heroes weapon store say that it has a high rate of fire, short range and a 45-round magazine. It is the equivalent of the National ArmyAK-74, and costs 1120BF to buy (1200 for National players).
A second M16 was released as part of the Tier 1 event, named as the Tier 1 M16. This new M16 has an unusable scope, a 30-round magazine, a low rate of fire and a long effective range. The Tier 1 M16 costs 1200BF to buy for an unlimited duration, and is only available to the Royal Army.