F-4. The M249 light machine gun is organic to the Infantry platoon and squads. It provides rifle squads with a light automatic weapon for employment during assault. (See figure F-1, page F-4.) The M249 also can be used in the medium machine gun role in defensive missions or support-by-fire position. The M249 fires from the bipod, the shoulder, the hip, or from the underarm position. The hip and underarm positions normally are used for close-in fire during an assault when the M249 gunner is on the move and does not have time to set the gun in the bipod position. It is best used when a high rate of fire is needed immediately. Accuracy of fire is decreased when firing from either the hip or shoulder.
F-5. Available M249 ammunition is classified as follows (see table F-2):
- M855 5.56-mm Ball. For use against light materiel and personnel, but not vehicles.
- M856 5.56-mm Tracer. Generally used for adjustments after observation, incendiary effects, and signaling. When tracer rounds are fired, they normally are mixed with ball ammunition in a ratio of four ball rounds to one tracer round.
- M193 5.56-mm Ball. M193 ball ammunition can be fired with the M249, but accuracy is degraded. For this reason, it only should be used in emergency situations when M855 ball is not available.
- M196 5.56-mm Tracer. M196 tracer ammunition can be fired with the M249, but accuracy is degraded. For this reason it only should be used in emergency situations when M856 ammunition is not available.
Note. The M249 SAW might be replaced by the MK48 light machine gun (LMG).