Infantry Drills

F-146: Machine Guns in the Defense

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F-146. The platoon’s defense centers on its machine guns. The platoon leader sites the rifle squad to protect the machine guns against the assault of a dismounted enemy formation. The machine gun provides the necessary range and volume of fire to cover the squad’s front in the defense.

F-147. The primary requirement of a suitable machine gun position in the defense is its effectiveness in accomplishing specific missions. The position should be accessible and afford cover and concealment. Machine guns are sited to protect the front, flanks, and rear of occupied portions of defensive positions, and to be mutually supporting. Attacking troops usually seek easily-traveled ground providing cover from fire. Every machine gun should have three positions: primary, alternate, and supplementary. Each of these positions should be chosen by the leader to ensure his sector is covered and machine guns are protected on their flanks.

F-148. The leader sites the machine gun to cover the entire sector or to overlap sectors with the other machine guns. The engagement range may extend from more than 1000 meters where the enemy begins his assault to point-blank range. Machine gun targets include enemy automatic weapons and command and control elements.

F-149. Machine gun fire is distributed in width and depth in a defensive position. The leader can use machine guns to subject the enemy to increasingly devastating fire from the initial phases of his attack, and to neutralize partial successes the enemy might attain by delivering intense fires in support of counterattacks. The machine gun’s tremendous firepower enables the unit to hold ground. This is what makes it the backbone or framework of the defense.

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Go Back To: U.S. Army FM 3-21.8: The Infantry Rifle Platoon and Squad