Glossary

Air-delivered bomb

Air-delivered bombs are bombs that are dropped from an aerial vehicle and designed to achieve a state of free fall as they reach the intended target or target area. When compared to other munition categories, they are typically large. They range vastly in weight, from only a few kilograms to more than 2,000 kilograms – roughly the weight of a car.

Artillery gun

A gun designed to engage targets at the limits of, or beyond, a user’s line-of-sight (i.e., those weapons capable of long-range fire, typically indirect fire).

Artillery gun projectile

Gun-launched indirect-fire projectiles that are typically unguided. Compared to other munition categories, they are relatively short and have a typical range of 30-40 kilometres.

ballistic trajectory

The form of motion experienced by an unpowered, unguided munition that moves along a curved path under the action of only gravity and drag (air resistance). These flight paths generally resemble a parabola.

Breech

The rear opening of a barrel (opposite the muzzle), usually containing the chamber of the gun.

Calibre

The nominal diameter of a projectile. For larger munitions, most often measured in millimetres (e.g. 152 mm artillery gun projectile).

driving band

A soft metal band around a projectile, usually located near its base. It centres the projectile and makes it fit tightly in the bore, thus preventing the escape of gas. When a projectile with a driving band is fired from a rifled barrel, the driving band engages the rifling and imparts spin to the projectile. Sometimes referred to as a ‘rotating band’.

fins

A fixed or adjustable vane or aerofoil affixed longitudinally to an aerodynamically or ballistically designed body for stabilising or control purposes.

Fuze

A mechanism with explosive components designed to initiate a train of fire or detonation in a munition by a mechanical, chemical, or electrical action.

Gun

A weapon which uses the combustion of a propellant to generate high-pressure gas in a sealed chamber in order to accelerate a projectile in a controlled manner.

Hydraulic and/or electronic components

Portions of the munition that make up hydraulic or electrical control sections. In general, more sophisticated munitions, such as guided missiles, will have a greater percentage of these components.

Indirect fire

Fire directed at targets which may or may not be within the operator’s line-of-sight, where the weapon is not aimed directly at the target (i.e., fire which uses the arcing trajectory of a projectile and/or the guidance characteristics of a munition to strike targets).

Missile

A powered munition with the ability to alter its trajectory once it has been launched.

Mortar gun

A relatively short-barrelled gun designed for indirect fire which fires low-velocity projectiles.

Mortar projectile

Mortar projectiles are gun-launched indirect-fire that are typically unguided. Mortar projectiles generally consist of a fuze (most often mounted in the nose of the munition), a body with one or more obturating rings, and a tail assembly with flash holes and fins.

Munition

An expendable item which is designed to achieve operational effects by means of an effect mechanism, and which travels from a source (e.g., individual weapon, vehicle-integrated weapon, etc.), via a method of delivery (e.g., emplaced by hand, fired from a gun, etc.), to a target or target area.

Muzzle

The end of a gun barrel through which projectiles exit.

obturating ring

A recessed groove around the body of a mortar projectile that is designed to trap gas when the projectile is fired, thus permitting the gas to propel the munition out of the barrel. Multiple obturating rings are normally arranged together and are located at the widest portion of the munitions body. Sometimes these grooves are covered by a plastic band. Sometimes ‘obturation ring’, ‘gas check ring’, or ‘gas check band’.

Powered munition

A munition which features an onboard propulsion method (e.g., a rocket motor) to maintain or adjust its rate of travel.

Precision guided munitions

Munitions, both powered and unpowered, which can alter their flight paths to strike a target with a high degree of precision.

Pre-fragmented body

The body of a warhead or explosive payload of a munition which is pre-scored or pre-cut in a deliberate pattern so that it breaks into uniform fragmentation more easily upon detonation. The scoring may be visible on the outside, inside, or both sides of the warhead body.

Projectile

An object initially projected by an applied exterior force and continuing in motion by virtue of its own inertia, such as a bullet or hand grenade. Smaller projectiles (those fired from firearms) are often known as ‘bullets’, whilst certain larger projectiles (e.g., artillery gun projectiles) are sometimes referred to as ‘shells’.

Rifling

A pattern of (generally helical) grooves in the bore of a barrel which are designed to impart spin to a fired projectile. This rotation provides gyroscopic stability to the projectile, increasing accuracy and precision, and ensuring the projectile flies point-first toward the target.

Rivet

A short metal pin or bolt for holding together two plates/pieces of metal. rivets are commonly used in munition construction.

Rivet hole

The hole occupied by a rivet (whether present or not).

Rockets and missiles

Rockets and missiles are two closely related types of powered munitions which utilise an internal propulsion method, commonly called a rocket motor, to maintain their rate of travel after launch. While missiles are generally guided and contain electronic parts, rockets have no guidance system.

Rocket motor

A reaction propulsion system which derives its thrust from the ejection of hot gases generated by the burning of propellant.

Strike line

A distinctive fragmentation pattern created by the detonation of artillery projectiles.

Suspension lugs

An assembly with one or more mounting holes that is affixed to munitions which are carried under the wings or body of an aircraft, designed for the purpose of suspending these munitions below the airframe. The lugs are held by a variety of gripping mechanisms, which release their hold when the munition is dropped or separated from the aircraft.

tailfins

Fins located in the rearward section of a munition.

Thick-walled body

When the body of a munition’s warhead or payload constitutes a relatively high percentage of the munition’s overall weight, it is usually referred to as ‘thick-walled’. Often, the reason for the notable thickness is that the body is intended to become lethal fragmentation upon the munition detonating and/or the munition requires a heavier construction for structural reasons (e.g., to withstand the pressures of being fired from a gun).

Thin-walled body

When the body of a munition’s warhead or payload constitutes a relatively low percentage of the munition’s overall weight, it is usually referred to as ‘thin-walled’. These munition bodies are usually only intended to serve as a container for the contents and are therefore designed to be as light as possible (e.g., many guided missile designs).

venturi nozzles

Constricting openings in rocket motors that increase the velocity and pressure of existing gases.

welding seams

When referring to the body of a munition, these are the junctions where sections have been connected by one of a variety of methods of welding. When the munition suffers an impact or a detonation, the body will often separate along these seams.

 

For more conflict and munition-related terms, Armament Research Service (ARES) has produced a full 2022 glossary.

All images copyright Airwars/Azul de Monte.