What is the function of the charging handle in the M16A3/M4A1 service rifle?

The charging handle in the M16A3/M4A1 service rifle serves the primary function of cocking the weapon. When the charging handle is pulled to the rear, it retracts the bolt carrier group, which in turn compresses the firing pin spring and moves the firing pin into the cocked position. This is essential for the weapon to function properly, as it prepares the firing mechanism to fire a round when the trigger is pulled.

The operation of the charging handle also allows for the chambering of a round from the magazine into the chamber once released. Thus, the charging handle not only cocks the weapon but also facilitates the loading process, making its role crucial in preparing the rifle for firing.