Barrel
The metal tube through which a projectile or shot charge is fired.
Cartridge
Unfired ammunition of handguns and rifles.
Lands
Bore of the barrel that has raised areas.
Semiautomatic
Any weapon where the shooter pulls the trigger, one bullet is fired and a new bullet is automatically loaded.
Example of a caliber:
A common metric caliber is 9mm. Can also be .22, .45, .357.
Bore
The inside of a barrel.
Ejector
Designed to eject the fired cartridge case from the firearm.
Primer
The shock-sensitive explosive that is placed in the cartridge at the factory. Causes the gunpowder to ignite.
Shell
Ammunition of shotguns.
Example of a rifling:
Broach cutting, button rifling, and hammer forging.
Bullet
A metal projectile for firing from a rifle, revolver, or other small firearm, typically cylindrical and pointed, and sometimes containing an explosive.
Gauge
A unit of measurement used to express the inner diameter (bore diameter) of the barrel.
Revolver
A repeating handgun that has at least one barrel and uses a revolving cylinder containing multiple chambers for firing.
Striations
The markings that are left on bullets by the machining process and cutting of the rifling in the barrel.
Example of a tool mark:
Impressed mark, crushed mark, striated mark, etc.
Breechblock
The part of the firearm action that closes the breech of a breech loading weapon before or at the moment of firing.
Extractor
A hook designed to grab the cartridge case and pull it from the barrel after firing.
Projectile
An object propelled by the force of gases produced by rapidly burning gunpowder.
Slide
The upper part that reciprocates with recoil during the gun's operating cycle.
Example of a gauge:
12-gauge is the most common shotgun.
Caliber
The diameter of the bore measured from land to land, usually expressed in hundredths of an inch (. 22 cal) or in millimeters (9mm).
Grooves
The raised portions of the rifling are known as lands and the recessed portions
Rifling
The process of cutting spiral grooves in the bore of the barrel of a firearm.
Tool marks
The impressions or indentations left on surfaces by tools or other objects.
How are revolvers different from semi-automatic weapons?
Revolvers are simple to operate - there is no slide to rack and no magazine to fill and insert. However, revolvers generally do not have the ability to hold as many rounds as semi-automatic weapons of the same size.