M4 carbine

The M4A1 Carbine is a firearm tracing its lineage back to the earlier carbine versions of the M16, all based on the original AR-15 made by ArmaLite. It is a shorter and lighter version of the M16A2, with 80% parts commonality with the M16A2. The M4A1 has selective fire options including semi-automatic and full-auto. It fires the 5.56x45mm NATO, and is suitable for C.Q.C. Although the M4 has less effective range than the longer M16, many military analysts consider engagement with a non-specialized small arm above a range of 300 meters (330 yd) to be unnecessary. It is effective at ranges of 150 meters (160 yd) or less and has a maximum effective range of about 500 to 600 meters (550–660 yd).

Battlefield 2
The M4A1 Carbine is the standard primary weapon for the USMC in the Special Forces kit. It has a Tasco Red Dot Sight attached to it. It does low damage per shot but has a good rate of fire and low recoil in full auto mode, making it an effective weapon in many situations.