Forensic Ballistics : FIREARM

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H
ave you ever seen a crime scene where there is bullets involved and see the investigators solve the case using the bullets available?
Well that’s what we are here to discuss with. The science that deals with the projectiles and missiles with their motion and related phenomenon for application of justice is called as Forensic ballistics.
This term was 1st coined by Calvin Goddard.


The types of Forensic ballistics –
1.    Internal Ballistics
2.    External Ballistics
3.    Terminal Ballistics

Components of Forensic ballistics –
1.    Firearm
2.    Ammunition
3.    Target

Internal Ballistics signifies the activities going inside the firearm.

External ballistics signifies the action of the ammunition as it moves out of the firearm into the environment.

Terminal Ballistics signifies the action of the ammunition inside the target or onto the target as it hits.

Firearm is a instrument used to fire the projectile into the particular direction with a great force. The projectile can be a bullet or a missile. According to the firearm act 1959, anything that is thrown which is explosive or has a huge amount of energy is a firearm, it includes artillery, hand grenades, riot pistols, noxious gasses, or such thing.

Parts of firearm –
1.    Barrel
2.    Stock
3.    Action (trigger)
4.    Chamber
5.    Extractor
6.    Leed
7.    Breech
8.    Muzzle
9.    Firing pin or striker.


Classification of Firearms –
1.    Single shot – the gun has to be loaded after each shot. Shotguns come under this category.
2.    Repeaters – manual loading or extraction of the ammunition is done after shooting takes place, this is seen in revolvers and some rifles.
3.    Semi-automatic – ammunition is extracted after it is completely emptied from the firearm and the ammunition is fired as long as the trigger is pulled. To shoot again, the trigger is pulled again. May include some SMG’s (sub machine guns).
4.    Automatic – Similar to semi-automatic but the extraction and reloading of ammunition is done as long as the trigger is pulled.
Parts of firearm. (breech is the posterior aspect from where loading can take place).

Firearms can also be classified according to the loading style of the ammunition.
1.    Breech loader
2.    Muzzle loader
3.    Magazine loader

Other way of classifiying is the usage –
1.    Primary firearm
2.    Secondary firearm or sidearm (generally pistols and revolvers)

Other way is based on action –
1.    Pump action
2.    Bolt action
3.    Break action
4.    Lever action

Other way is based on the positioning while shooting –
1.    Hand held – pistols and revolvers
2.    Shoulder supported – rifles, snipers, shotguns etc.

The barrel of the gun is another way of classifying the firearm. Depending upon the barrel they are classified as –
1.    Smooth bore
2.    Rifled bore

Rifled bore guns have a spiralling groove inside the barrel. The number of spiralling is dependant on the gun manufacturer and thus is another important point in identification. Thus, the guns with the rifling are called as RIFLES. The rifling helps in the forward projection of the ammunition in the air with speed while maintaining the trajectory.

The bumps are called as lands and the depression in between any two lands is called as groove.

 Some images of the guns..
Try to identify by commenting down in comments.

a.                                                  b.

c.                                                                   d. 
 

e.                                                                

f.

g.

Answers will be uploaded on the instagram page soon.
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