Which function comes first in the cycle of operation for the M4/M16 series rifle?

In the cycle of operation for the M4/M16 series rifle, feeding is the first function that occurs. This process involves the cartridge being moved from the magazine into the chamber of the rifle. The feeding function is crucial because it sets up the scenario for subsequent operations. If feeding does not occur properly, the rifle cannot load a cartridge to be fired.

Once the cartridge is correctly fed into the chamber, the next steps in the cycle can follow, including chambering the round, firing it, and finally ejecting the spent casing. Each step builds on the previous one, demonstrating the importance of an efficient feeding mechanism in the overall functioning of the weapon system.