Ballistics Vocab

Ballistics

Scientific study of the motion of projectiles in flght.

Caliber

The bore of a firearm or the cartridge that it fires.

Bore

The interior diameter of a gun barrel.

Gauge

The interior diameter of a shotgun barrel determined by the number of lead balls fit in the barrel to make one pound.

Shot

lead spheres in a shotgun shell.

Slug

A single shot or bullet in a shotgun shell.

Grains

The basic unit of weight in the British system (based on a grain of barley).

Still used as a unit of weight today for metals, gems, gunpowder, and bullets.

Rifled

The bore of a gun barrel that has been made to form a grooved spiral.

Lands

The raised area between 2 grooves in the rifling of a gun barrel that impart grooves on the bullet.

Grooves

Spiral cuts in the bore of a barrel that give the bullet its spin.

Striae

Parallel sets of scratches on a bullet caused by unique markings in the bore of a rifled weapon.

Cannelures

Grooves around a bullet that provide a means of crimping the cartridge case to the bullet.

Head Stamp

Numerals, letters, and symbols on the base of a cartridge showing the manufacturer, caliber, and code.

Breech

Portion of the gun that contains the firing mechanism.

Extractor

Hooked part attached to the breechblock which withdraws the spent casing from the chamber when the breechblock separates from the barrel after firing.

Ejector

The part on the firearm whose function is to throw a spent casing from the gun after firing.

Magazine

A container that holds cartridges under spring pressure to be fed into the gun’s chamber. (also called clip)

Chamber

Part of the firearm that contains a cartridge for firing.

Griess Test

A color test for the presence of nitrite in gunpowder residue.

GSR

Gunshot residue consisting of burned and unburned powder, vaporized and particulate lead, primer residues of lead, barium, and antimony.

Sodium Rhodizonate Test

A color test for the presence of lead in gunshot residue.

Buffer

A solution containing either a weak acid and its salt or a weak base and its salt, which is resistant to changes in pH.