I Glossary
A
Acetone
A colorless flammable solvent used in the manufacture of smokeless powder and double-base propellants. Also known as dimethyl ketone.
Audit trail
A system of record keeping based on information of manufacture, distribution, and/or retail sale of a commercial product by which that product can be traced from its manufacturer to its retail purchaser.
B
Ball powder
Spherical smokeless powder produced by precipitation in water and flattened to various thicknesses to achieve a wide variety of ballistic performance.
Base grain
Smokeless powder that has neither a deterrent coating nor a graphite glaze.
Black powder
A deflagrating intimate physical mixture of sulfur, charcoal, and an alkali nitrate, usually potassium, but sometimes sodium nitrate.
Black powder replica
An intimate physical mixture of materials similar to those used in the manufacture of black powder designed to replace black powder in some sport-shooting applications. Compositional differences may include replacement of charcoal with compound such as sugar or ascorbic acid as fuels, and addition of other chemicals.
Bulk explosive
An unpackaged explosive that is typically shipped in trucks directly to the end user for consumption.
C
Caliber
Nominal bore diameter of a gun. Can be expressed in decimal inches (such as .22 caliber) or in millimeters (such as 5.56 mm).
Calorie
The unit of heat required to raise the temperature of 1 gram of water by 1 °C.
Canister
Small package of smokeless powder or black powder, typically in 1-pound, 4-pound, 5-pound, and 8-pound sizes, suitable for hand-loading and muzzle-loading purposes. The package is typically lightweight fiber or plastic construction, designed to vent quickly and prevent pressure buildup if accidentally ignited.
Cartridge-actuated device (CAD)
A self-contained device employing smokeless powder or black powder as the primary source of working gas to drive a piston to do mechanical work. Examples include air-bag-inflation devices, bomb-ejection cartridges, cable cutters, fire-extinguishing systems, parachute-release mechanisms, flight-recorder-ejection systems, and aircraft-seat-ejection units.
Centerfire
A type of small arms ammunition that uses a replaceable primer in the base of the cartridge.
Centralite
Generic name for a family of chemical stabilizers (for nitrocellulose) developed in Germany at the Central War Laboratory near Berlin about 1906.
Coincident gamma-ray emitter
A radioactive material that, upon decay, simultaneously releases two gamma rays, thereby making it detectable by use of several counters with coincident decision logic.
Combustion
A self-sustained chemical reaction with the evolution of heat and flame, proceeding at a controlled rate at considerably less than the speed of sound in the reacting medium, as opposed to the supersonic shock wave of detonation.
Commercial explosive
An explosive designed, produced, and used for commercial or industrial applications rather than for military purposes.
Comminution
The process of reducing the size of solid materials to a fine powder or dust through milling or crushing.
Compatibility
Lack of chemical reaction between a foreign material and an energetic material at elevated temperature. Normally measured by such thermal stability tests as Differential Scanning Calorimeter, Taliani Heat Test, and Vacuum Stability Test.
Composite propellant
A propellant in which the fuel and the oxidizer are separate materials, typically consisting of a blend of a crystalline oxidizer (such as sodium nitrate or ammonium perchlorate) and an amorphous or plastic fuel (such as a synthetic rubber) that acts as both fuel and binder.
Containment
The packaging required for an energetic material to explode by providing a fixed volume for the gaseous products of the combustion process. Also used in bombings to provide fragmentation designed to injure or kill bombing victims (e.g., metal pipe, polyvinyl chloride tubing, plastic bottles, or cardboard).
Corning mill
A set of calender rolls used for particle size reduction in the manufacture of black powder.
Curie
A unit of radioactivity equal to 3.7 x 1010 disintegrations per second.
D
Deflagration
Extremely rapid combustion, but not detonation. Sometimes used for the burning of explosive materials without the use of atmospheric oxygen.
Detection taggant
See Marker.
Deterrent
(1) Any action, process, or material that reduces the likelihood that a potential bomber will attempt an illegal bombing. (2) A surface coating applied to smokeless powder to retard the initial burning rate, initial gas generation rate, and initial flame temperature; sometimes known as a surface moderant. Typical concentrations are 1 percent to 10 percent.
Detonation
An explosive reaction initiated by a high-pressure shock wave, which propagates at a velocity higher than the speed of sound in the material and is supported by the energy released by the reaction.
Dibutyl phthalate
A colorless oily liquid commonly used as a nonenergetic plasticizer for nitrocellulose in smokeless powder.
Dinitrotoluene (DNT)
A viscous liquid nitrated product of toluene. Formerly used as a deterrent coating in smokeless powder prior to stringent restrictions in the 1980s by the U.S. Environmental Protection Agency. Not used today.
Disk powder
An extruded granule of smokeless powder that is cut as a flake and may be perforated.
Double-base
Propellant or smokeless powder based on nitrocellulose and nitro-
glycerin as the energetic materials. Invented by Alfred Nobel in 1887. The nitroglycerin content may vary from 7 percent to 40 percent.
E
Ether
A colorless, highly flammable solvent used in the manufacture of smokeless powder and single-base nitrocellulose propellants. Also known as diethyl ether.
Ethyl alcohol
Grain alcohol; also known as ethanol. Colorless solvent used in the manufacture of smokeless powder and nitrocellulose-based propellants.
Ethyl centralite
A solid used as a stabilizer for nitrocellulose and smokeless powders to retard thermal decomposition and extend shelf life to several decades. In smokeless powder containing nitroglycerin, ethyl centralite is more effective than diphenylamine. Chemically known as diethyl diphenyl urea.
Exothermic
A chemical reaction that generates heat.
Explosion
A rapid expansion of matter into a volume much greater than its original volume.
Explosive material
Materials including explosives, blasting agents, and detonators. The term includes, but is not limited to, dynamite and other high explosives; slurries, emulsions, and water gels; black powder and pellet powder; initiating explosives; detonators (blasting caps); safety fuse; squibs; detonating cord; igniter cord; and igniters.
A list of explosive materials determined to be within the coverage of 18 U.S.C., Chapter 40, Importation, Manufacture, Distribution and Storage of Explosive Materials, is issued at least annually by the Director of the Bureau of Alcohol, Tobacco, and Firearms of the Department of the Treasury.
F
Flash suppressant
A chemical substance added to smokeless powder to reduce or eliminate visible muzzle flash.
Fragmentation
Tangible physical objects or missiles propelled outward to high speeds by an explosion, or the process in which such objects are produced. Metal, plastic, or glass pipe bomb casings can be ruptured by the high-pressure product gases of an explosive filler to produce high-speed fragments. Articles such as BBs, screws, nails, nuts and bolts, marbles, and ball bearings inside or affixed to a pipe-bomb casing are called shrapnel or langrage (also langridge) and are intended to increase the lethality of the bomb. Military bomb and warhead casings rupture in the shock front of a detonating high-explosive filler and produce very sharp, very high speed fragments, also called shrapnel. The Department of
Defense Explosive Safety Board defines a hazardous fragment as one with an impact energy of 58 foot-pounds of force (79 joules) or greater. A missile with much less kinetic energy can produce a serious injury, but it is likely that, on average, a missile impacting with 58 foot-pounds of force will ensure a casualty.
Fuel
A chemical substance requiring oxygen for complete combustion. In black powder, charcoal and sulfur are fuels.
G
Gamma ray
Penetrating electromagnetic radiation of very short wavelength (less than 0.1 nanometer), especially that emitted by a nucleus in a transition between two energy levels.
Glazing
The process of coating and polishing the surface of black powder and smokeless powder to improve conductivity, reduce static electricity buildup, to improve the flow properties during loading of ammunition, to increase the packing density of smokeless powder in cartridges, and to improve ignition by improving the flame spread from grain to grain.
Grain
Term used to describe a definite geometrical shape of smokeless powder or black powder; often confused with a unit of weight where 1 pound is equal to 7,000 grains.
H
Half-life
The time required for the intensity of a radioactive material to decrease to one-half its initial value.
Hand loading
(Also known as reloading) The process of reusing cartridge cases repeatedly with new charges of smokeless powder, primer, and bullet (projectile). The cartridges are loaded individually by hand, and used repeatedly before discarding for the purposes of reducing cost or manipulating ballistic performance.
Hangfire
A noticeable delay in ammunition that occurs after a primer fires, and before the propellant charge ignites. In some instances, the delay may be several seconds or longer.
High explosive
An explosive characterized by a very high rate of reaction, development of high pressure, and the presence of a detonation wave in the explosion.
I
Identification taggant
See Taggant.
Improvised explosive
Explosive material that was not manufactured commercially.
Improvised explosive device
A mechanism such as a pipe bomb fabricated from explosive, commercial, or homemade materials.
IMR
A single-base smokeless powder, originally produced by DuPont, and known as improved military rifle powder. IMR powders are now produced by Expro in Valleyfield, Quebec, Canada. Characterized as a single-perforated cylinder with a deterrent coating.
Inert
Nonreactive or nondetonable. Some ingredients of smokeless powder are referred to as inert, meaning that they contribute no energy but are consumed during combustion.
Initiator
Represents a broad spectrum of small devices that function either by mechanical or electrical impulse and that are used to provide a flame for propellants or a detonation wave for explosives. An initiator can be a detonator, detonation cord, or similar device used to start detonation or deflagration in an explosive material. When used with smokeless powder or black powder, an initiator produces a flame used to start combustion and normally does not produce detonation.
J
Joule
A unit of energy approximately equal to 0.239 calories.
L
Lift charge
Granulated black powder used to propel aerial display fireworks into the air. The burning characteristics of black powder substitutes and smokeless powders make them unsuitable for use as lift charges.
Low explosive
A commonly used term for propellants, or explosives designed to burn rather than detonate.
M
Magazine
A building or structure used to store explosives, smokeless powder, or black powder.
Marker
A material (or tracer element) added to explosives that can be sensed by an associated detection instrument. Explosives that contain such a marker are considered "marked."
Mesh
Refers to the screen or sieve size, as measured by the diameter of the opening. For example, 30 mesh is equivalent to 600 microns.
Methyl centralite
A solid chemical used as a stabilizer for nitrocellulose and smokeless powders to retard thermal decomposition, chemically known as dimethyl diphenyl urea.
Micron
A unit of length defined as 1 x 10-6 meters.
Muzzle-loading
The process of using black powder (or a black powder substitute) in a gun designed solely for black powder. Such guns can only be loaded from the muzzle and are not capable of withstanding the high pressures generated by smokeless powder. Such muzzle loaders are common in Civil War reenactments and are not classed as firearms.
N
Nitrocellulose (NC)
An energetic fibrous polymer derived from the nitration of cellulose and characterized primarily by the degree of nitration. Smokeless powder typically uses nitrocellulose of 13.1 percent to 13.3 percent nitrogen, where the theoretical maximum nitrogen content is 14.14 percent.
Nitroglycerin (NG)
An energetic colorless liquid manufactured by the nitration of synthetic or natural glycerin. Used to plasticize nitrocellulose in double-and triple-base propellants.
Nitroguanidine (NQ)
A moderately energetic solid incorporated in some propellants as a coolant and flash suppressant to produce with nitroglycerine and nitrocellulose a triple-base propellant. Not normally found in commercial smokeless powders.
Nonideal explosive
An explosive that releases its energy slowly following shock compression and heating. It usually exhibits thicker reaction zones and contributes a smaller fraction of its total energy toward supporting the shock wave.
O
Opacifier
Used in smokeless powder to prevent radiant energy (during combustion) from penetrating the surface and producing wormholing. Typically, carbon black is used for this purpose at a concentration of 0.1 percent to 0.5 percent,
Original equipment manufacturer (OEM)
As used in this report, OEM refers to the commercial ammunition manufacturer that loads smokeless powder into cartridges.
Oxidizer
A chemical that yields oxygen to promote the combustion of a fuel. In black powder, potassium nitrate is an oxidizer.
Oxygen balance
The amount of oxygen in excess of that required for complete combustion of carbon to carbon dioxide and hydrogen to water, expressed as a weight percent or grams of oxygen per 100 grams of material. A negative oxygen balance, as found in most smokeless powders, denotes a deficiency of oxygen after combustion.
P
Packaged explosive
An explosive material manufactured, sold, and used in the form of individual cartridges or containers.
Pipe bomb
A type of improvised explosive device containing an energetic material filler (most commonly, but not necessarily propellant) enclosed by metal, polyvinyl chloride, cardboard, or other material cylinders, often with additional fragmentation devices for increased antipersonnel effect.
Plasticizer
A liquid that dissolves or swells a polymer to impart better processability, to waterproof the propellant, reduce brittleness, and tailor the energy level. Plasticizer can act either as a coolant or a source of energy. Typically used at a concentration of 2 percent to 40 percent.
Polyvinyl chloride
A common industrial and household plastic used primarily in piping.
Precursor chemical
A chemical used to synthesize an explosive material through a chemical process or as a component in a mixture that enhances the destructive force.
Primer
A small initiating device used to ignite smokeless or black powder. Can function by the stimulus of either mechanical action or electrical discharge. Typically, primers are located in the base of the cartridge case and are replaceable after firing.
Propellant
A chemical mixture such as black or smokeless powder that burns in the absence of atmospheric oxygen at a self-sustaining, exothermic, controlled subsonic rate, generating heat and gas, and capable of performing mechanical work.
Propellant-actuated device (PAD)
See Cartridge-actuated device.
Pyrotechnic composition
A mixture of chemical compounds and/or elements which is capable upon ignition of a self-contained and self-sustained exothermic reaction, for the production of heat, light, sound, gas, smoke, and/or motion.
R
Reloading
See Hand loading.
Residue
Any energetic material that has not been completely consumed in the intended application and can be recovered for laboratory analysis.
Rework
The process of recycling material in manufacturing operations to eliminate waste and scrap, which otherwise would require open burning or disposal.
Rework from partially processed material is recycled to the beginning step of the manufacturing.
Rimfire
A low-cost small-arms cartridge (usually .22 caliber) with the priming compound contained in the rim. Because the cartridge is deformed during firing, it cannot be reloaded. As opposed to centerfire, which has a cavity for a replaceable primer.
Rolling
A process of size reduction during the manufacture of smokeless powder, in which the propellant is passed between a pair of rolls (also known as calender rolls used in papermaking) separated by a very small adjustable space.
S
Saltpeter
Potassium nitrate.
Shock wave
A high-pressure wave or pressure disturbance traveling at a speed faster than sound in that medium.
Single-base
Smokeless powder or propellant based solely on nitrocellulose as the energetic material.
Small arms
Guns, typically handheld, or ammunition for a gun, of less than 20mm caliber.
Smokeless powder
A granular, free-flowing, solid propellant of various morphologies, using nitrocelluse as an active ingredient. It is classified as single-base (with nitrocelluse as the only active ingredient), double-base (with nitrocelluse and nitroglycerin), or triple-base (with nitrocelluse, nitroglycerin, and nitroguanidine). Smokeless powder is commonly used in small-arms ammunition.
Solvent recovery
The process of capturing, recovery, and reuse of volatile, flammable processing solvents used in the manufacture of smokeless powder to avoid discharging the solvents into the atmosphere.
Solve rate
The percentage of bombing incidents for which a perpetrator can be identified.
Stabilizer
A chemical incorporated in solid propellant to react with the decomposition products and prolong the shelf life of the propellant. Typically used at concentration of 0.5 percent to 2 percent. When properly stabilized, smokeless powder has a shelf life of nearly 100 years at 20 °C.
T
Taggant
An additive (or tracer element) designed to survive an explosion and to be recoverable at the bomb scene, used to aid law enforcement personnel in
either tracing explosive materials to the last legal purchaser or to provide evidence against a known suspect.
Torr
A unit of measure for pressure, approximately equal to 0.02 pounds per square inch, or 133 pascals. Standard atmospheric pressure is 760 torr.
Tracing
The process of identifying a commercial product by use of an external agent and record keeping through the manufacturing, distribution, and sale of that product.
Triple-base
Solid propellant containing nitrocellulose, nitroglycerin (or, e.g. diglycol dinitrate), and nitroguanidine.
Tubular powder
An extruded form of smokeless powder cut into rods whose length either equals or exceeds their diameter. Most, but not all, examples will have a central perforation and will possess fairly uniform dimensions of length and diameter.
V
Vapor pressure
The pressure exerted by the vapor phase of a chemical in equilibrium with its solid or liquid phase.
Vinsol resin
A naturally occurring thermoplastic resin, extracted along with turpentine from tree stumps, and used in smokeless powder as a deterrent coating.
W
Web
The smallest dimension of a smokeless powder granule.
