FIREARM is a device that hurls the projectile with a force that is supplied by the expansion of gases produced from the burning of a propellant.
Firearms are classified into two i.e., Primitive and Modern Firearms.
Primitive firearms include five types of firearms.
- HAND CANNON: It was the earliest type of handgun made of wrought iron or bronze. It was fitted into a frame with leather thongs. These were loaded from the muzzle end with powder, wad, and ball. On igniting the priming charge through the touch hole with a hot iron, fire flashed through the touch hole and then into the main powder charge to discharge the weapon.
- MATCH LOCK: the entire system and working were similar to hand canon. The only difference in this weapon was the “match” (a slow-burning piece of cord) used to ignite the priming charge was held in a curved hook screwed onto the side of the frame. To fire, the gun hook was slightly pushed forward to drop the burning end of the match on the priming charge.
- WHEEL LOCK: it consisted of a serrated wheel that was mounted on the side of the weapon at the rear end of the barrel. The wheel was spring-loaded with a chain around its axle. On turning the wheel with the spanner, the chain wound around the axle, and the spring was tensioned. A simple bar chain prevented it from unwinding until released with the trigger. Part of the wheel protruded into the pan containing a priming charge. The serpentine had a piece of iron pyrite fixed in its jaws. On pressing the trigger, the bar was withdrawn, which then turned on its axle. Sparks produced from the friction of pyrite on the serrated wheel ignited the priming charge, which in turn ignited the main charge and fired the weapon.
- FLINTLOCK: The ignition system was a simple mechanism that provided a spark by striking a piece of flint against a steel plate. The jaws held the flint on a pivoted arm, called the cock. The steel, which was called the frizzen, was placed on another pivoting arm opposite the cock, and therefore the pan containing the priming compound was placed directly below the frizzen. Upon pulling the trigger, a robust spring swung the cock in an arc so that the flint struck the steel a glancing blow. The blow produced sparks that dropped into the priming pan, which in turn ignited the priming powder. A flash was produced on igniting the priming charge that traveled through the touch hole, which ignited the main charge, and the weapon was discharged.
Three basic types of a flintlock are:
- Snaphaunce: it was a weapon with the mainspring inside the lock plate and a priming pan cover that had to be manually pushed back before firing.
- Miquelet: a weapon with the mainspring outside the lock plate, but with a frizzen and priming pan cover all in one piece. In this, the pan cover was automatically pushed out of the way the flint struck the frizzen.
- True flintlock – a weapon with a mainspring inside the lock plate and with the frizzen and priming pan cover in one piece. This also had a half-cock safety position enabling the weapon to be carried safely with the barrel loaded and priming pan containing the powder.
- PERCUSSION SYSTEM: In this type of weapon, a percussion cup was introduced. This weapon made use of mercury fulminate as the primer. The compound exploded on being struck. When a hammer struck mercury fulminate, a flash was produced, which was strong enough to ignite the main charge powder in the barrel.
Modern firearms can be further classified based on action, loading characteristics, bore characteristics, size of the firearm, firing pin characteristics, and use.
Classification of Modern Firearms Based on Action
It’s that part of the firearm that helps in loading fires and ejecting a cartridge. Lever action, pump action, bolt action, and semi-automatic are included in this.
- LEVER ACTION: The type of firearm consists of the lever, which is pulled down and then back up to expel out the old cartridge and load a new round in the weapon.
- PUMP ACTION: These are primarily shotguns. This works on a pump-action created when the user slides the lever. This brings a new round into the chamber, expelling out the old cartridge.
- BOLT ACTION: It works by manually manipulating the bolt through the bolt handle placed on the right side of the weapon.
- SINGLE ACTION: in such firearms, the trigger serves only one purpose of dropping the hammer.
- DOUBLE ACTION: in such firearms, the trigger serves two purposes that are it cocks and releases the hammer.
Classification of Modern Firearms Based on Loading
- MUZZLE LOADING: A type of firearm in which the projectile and the propellant charge are loaded from the muzzle end of the gun.
- BREECH LOADING: A type of firearm in which the projectile and the propellant charge are loaded from the breech end of the firearm.
- MAGAZINE LOADING: A firearm that stores the projectiles in the magazine. The magazine is an ammunition feeding device that is detachable.
Classification of Modern Firearms Based on Bore Characteristics
The bore of a firearm is within the barrel. “Smoothbore” weapons (typically shotguns) have no rifling. However, most handguns and rifles have “rifling.”
Based on the bore of the hearth arm, it is classified into the following.
- SMOOTH BORE: These belong to the category of shoulder-arm, having a smoothbore barrel and are intended for firing lead shots (pellets) or sometimes one ball (slug), etc. Some shotguns have a small part of their bore rifled near the muzzle end, referred to as paradox guns.
- RIFLED BORE FIREARMS: these firearms have shallow spiral grooves cut on the part of the barrel, which imparts a spin to the projectile and helps stabilize the flight. Greater accuracy is imparted to the projectile in these firearms.
Classification of Modern Firearms Based on Size
Based on the dimensions of the firearms, it is usually classified into handguns and shoulder guns.
A handgun is a firearm short enough to be held in one hand. These firearms are short-barreled. The two major sub types of handguns are revolvers and pistols.
- Revolver: In a revolver, ammunition is held in a cylinder at the rear of the barrel, with each round having its chamber. Cocking the hammer rotates the cylinder via a ratchet mechanism to replace a new round of ammunition in line with the barrel. When the trigger is pulled, the hammer drops, which then fires the round.
- PISTOL: It is the general name for a short-barreled firearm. Pistols have a magazine, which is enclosed in its grip. These are available in all calibers from about 5 to12mm.
Pistols are generally semi-automatic or self-loader type and automated type.
The cartridge is fired with the pull of the trigger. The discharge is utilized for ejecting the fired cartridge cases, reloading a fresh round in the chamber, cocking the action so that the weapon is automatically made ready to fire again on pulling the trigger for a second time.
In these pistols, with the pull of the trigger, all the loaded cartridges in the magazine get fired one after the another and stop only when the trigger is release.
2. Shoulder Guns
These are the long-barreled firearm such as a rifle
- RIFLE: All rifled firearms fire a single bullet. They have a much longer barrel and can fire high-power ammunition. The rifled barrels are grooved, which gives gyratory motion to the projectile, which continues even in flight. The gyratory motion maintains the bulletin stable nose end flight, which reduces air resistance and enhances the degree of flight
Classification of Modern Firearms Based on Firing Pin
FIRING PIN is part of a firearm mechanism that strikes the primer of a cartridge to initiate ignition. Also called a striker. Based on the position of the firing pin, it is divided into three types
Rimfire: These firearms have primer on the rim of the cartridge. These are limited to low-pressure loads.
Centrefire: In this, the primer is present in the center of the cartridge case. They are used in rifles, shotguns, and handguns.
Pinfire: In this type, the primer in the cartridge is ignited by striking with a small pin protruding radially from above the base of the cartridge.
Classification of Modern Firearms Based on Use:
Based on the use, the firearm is classified into sports firearms used for sporting purposes in shooting academies and service firearms used by the armed forces.
Many serious crimes resulting in fatal death or grievous injury are often committed by using a firearm. The evidence related to firearm offenses usually centers around the fired bullet, the shell examined for determining the make of the gun from which it was fired.