Ballistics 4

lecture 4

main components of a firearm

Barrel

Magazine

Hand guard

Pistol grip

Trigger and the trigger guard. All firearms have a receiver

Bolt

The bolt is a mechanical part of a firearm (mostly semi-automatic pistols) that blocks the rear chamber while firing but moves aside to allow another cartridge to be inserted

breech

Holds the firing mechanism where the cartridge is inserted

Breech block

Movable part of the firing system that seals the movement of firing, preventing gases from escape. Most modern small firearms use a bolt

Chamber

Portion of the barrel or barrel extension which supports the cartridge case while it is in firing position

Clip

Device which contains several cartridges that is fed into the magazine of the firearm

Cylinder

Rotating part of the revolver that contain multiple cartridge chambers

Magazine

Ammunition storage and feeding device of a firearm within or attached to a repeating firearm

Slide

Houses the firing pin and the extractor and serves as the bolt

Trigger

Mechanism that actuates the firing sequence of the firearm

Action

The mechanism that loads, fires, locks, and ejects the ammunition. The action-type depends on the firearm type

Barrel

A long metal tube that extends from the frame and directs the bullet upon shooting the firearm. Barrel length varies by firearm type

Revolver

Is a short or hand-held firearm with a revolving cylinder typically of five to nine chambers, manually loaded with cartridges. As the cylinder rotates into position, the trigger can be pulled, releasing the hammer firing the cartridge. Expended cartridge cases remain in the cylinder until manually unloaded.

Action: Revolvers are usually repeating firearms. According to the system of operation of the trigger tail, revolvers can be of double (when the trigger also cocks the hammer) or single action (when the hammer is cocked manually

Pistol

Is a short or hand-held firearm designed for semi-automatic operation. The chamber is part of the barrel. Cartridges are generally loaded into a magazine, which is inserted into the grip. The action of the firearm feeds the next cartridge and expels the spent round.

Action: single shot, repeating, semi-automatic and automatic pistol.

Shotgun

Is a shoulder-fired long gun with one or two unrifled barrels (side-by-side or over configuration), usually designed to shoot many small projectiles ("shots") rather than a bullet. The caliber of a shotgun is referred to as the gauge and is usually larger in diameter than other small arms.

Action: Usually single-shot. May also be repeating, or semi-automatic 

Rifle or carbine

Is a shoulder-fired long gun, with a series of spiral grooves cut inside the barrel ("rifling") imparting spin to the projectile. Some rifles have a detachable magazine like the pistols described above, and others have integral magazines. A carbine resembles a rifle but has a shorter barrel.

Action: Single-shot, repeating, semi-automatic or fully automatic

Assault rifle

Can be considered a subcategory of rifles and represent ' any of various intermediate-range, magazine-fed military rifles (such as the AK-47 or M16) that can be set for automatic or semiautomatic fire

Action: Semi-automatic or fully automatic

Sub machine gun

It is a hand-held, lightweight short barreled machine gun consisting of relatively low-energy handgun-type cartridges and fired from the hand, hip or shoulder.

Action: Semi-automatic or fully automatic. Where the firing system is automatic, the firearm would be classified as an automatic pistol or automatic sub-machine gun.

Machine gun

It is a firearm that is capable of full automatic firing (more than one shot without manual reloading, by a single function of the trigger) and that fires rifle ammunition. It is generally crew-operated ('heavy machine gun'), but some forms may be fired by single individuals ('light machine gun'). Most machine guns have the ammunition fed by belts, although some use magazines.

Action: Semi-automatic or fully automatic

Crafted/improvised firearms

the practice consists of weapons and ammunition being fabricated by hand in relatively small quantities. Artisanal in nature, they can range from pistols and shotguns to the more advanced assault rifles. These arms manufactured by parts or components that were not originally designed to be parts of a firearm or made out of parts from other firearms.

Replica/imitation firearms

A replica firearm is a device that is manufactured to resemble an existing design of a firearm but is not intended to fire. Typically, replica firearms are manufactured for firearm collectors, especially collectors of antique firearms

Modular firearms

Modular weapons are produced with components that are interchangeable in a way that can change or improve the characteristic of a firearm. In addition, changing essential components like the barrel, extractor/ejector, firing pin etc. will make ballistic identification extremely difficult, if not impossible.

IBIS (integrated ballistic identification system)

technological weapon in the fight against gun violence. The IBIS search engine extends the capabilities of law enforcement agencies to quickly find links between firearm-related crimes

How IBIS works

IBIS uses specialized 3D microscopy to capture the unique marks left by firearms on fired bullets and cartridge cases.

An IBIS solution can start with one location and can extend to multiple sites, all contributing seamlessly within an integrated network.

IBIS makes it possible for agencies to collaborate across jurisdictions, both within a national program and internationally.

IBIS uses powerful algorithms to reveal the most likely matches within IBIS networks representing millions of bullets and cartridge cases.