M4 Carbine Operation Cycle: A Step-by-Step Guide

a. The shooter inserts a magazine containing ammunition into the magazine well.

b. The bolt is retracted, extracting any spent casing and cocking the hammer.

c. A fresh round is stripped from the magazine and chambered.

2. Firing:

a. The shooter presses the trigger.

b. The hammer is released, striking the firing pin.

c. The firing pin impacts the primer of the cartridge, initiating the combustion of the propellant.

d. The expanding gases propel the bullet down the barrel.

3. Unlocking:

a. As the bullet travels down the barrel, it pushes the bolt carrier rearward.

b. The cam pin on the bolt carrier rotates the bolt, unlocking it from the chamber.

4. Extraction:

a. The extractor on the bolt grabs the spent casing and pulls it out of the chamber.

5. Ejection:

a. The ejector on the bolt strikes the spent casing, ejecting it from the receiver.

6. Forward Assist:

a. The forward assist is sometimes engaged to help the bolt fully chamber the next round.

7. Rechambering:

a. The bolt is pushed forward by the recoil spring.

b. A fresh round is stripped from the magazine and chambered.

8. Ready to Fire:

a. The rifle is now ready to fire again, and the cycle of operations repeats.