The firearm is defined as a device by which a projectile or projectile can be hurled with an excellent force.
The modern firearm is classified based on several characteristics. Firing mechanisms involve the process such as loading of ammunition, chambering, locking, firing, unlocking, extracting, ejecting, and cocking.
This article further deals with the various stages involved in the firing mechanism.
Cycle of Operation of Firearms
- FEEDING
Feeding places around within the receiver just to the rear of the chamber. A spring-loaded follower accomplishes feeding in the magazine.
- CHAMBERING
This action is required to ram a fresh round into the chamber. The cartridge is now aligned into the chamber part of the barrel.
- LOCKING
Locking holds the bolt in its forward position for a brief period to avoid the loss of pressure until unlocked by other forces.
- FIRING
Firing occurs when the pin or the striker strikes the primer of the cartridge.
- UNLOCKING
Unlocking occurs after the firing of the round. Thus, actions for unlocking are just the reverse of the requirements for locking.
- EXTRACTING
The process of pulling the empty cases out of the chamber is referred to as extracting. The extractor (a small hooked piece of metal encased within the bolt) snaps over the rim of the cartridge case when the round is chambered.
- EJECTING
It is necessary to tug the cartridge case out of the chamber and throw it free from the receiver. This action is called ejection and is created by placing a small projection on one side of the receiver so that, as the bolt and case move to the rear, the case then strikes the projection and is expelled out of the weapon.
- COCKING
Cocking is the retraction of the firing mechanism against spring pressure so that there will be sufficient energy to fire the cartridge in the next cycle of operation.
Firing Mechanism of a Firearm
When the firearm’s trigger is pressed, it releases the hammer or the striker with considerable force. The striker compresses a pressure-sensitive material contained in the percussion cap. This generates a hot, piercing flame, which ignites the propellant charge. The charge quickly transforms into gas.
Due to limited space in the cartridge, the large volume of gas so produced develops a very high pressure. The pressure so developed forces out the bullet or the shot chare through the barrel towards the target. While the bullet moves forward, the cartridge case is pushed backward. The case, therefore, comes in contact with the firing pin and the breech face of the breechblock and picks up marks from their surface.
The cartridge, which also expands all around due to the tremendous pressure developed in it, comes in intimate contact with the chamber and sometimes may carry the chamber marks.
The fired cartridge case is extracted from the chamber by an extractor and then ejected out of the gun by an ejector. In the process, both extractor and ejector are likely to leave marks on the cartridge case. All these marks are beneficial, which can afford the identity of the bullet or the cartridge case with the concerned firearm.
