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B

Back-Blast
Rearward blast of gases from the breech of recoil-less weapons and rockets upon the burning of the propellant charge. It is sometimes referred to as breech-blast.
Bakelite
For its inventor, Leo Baekeland, a synthetic thermosetting phenol-formaldehyde resin with an unusually wide variety of industrial applications ranging from billiard balls to electrical insulation.
Ballistic Cap
Cap for projectile, designed to improve its ballistic efficiency.
Ballistic Coefficient
Measure of the ability of a missile to overcome air resistance.
Ballistic Conditions
Conditions which affect the motion of a projectile in the bore and through the atmosphere, including muzzle velocity, weight of projectile, size and shape of projectile, rotation of the earth, density of the air, elasticity of the air and the wind.
Ballistic Curve
Actual path or trajectory of a bullet or shell.
Ballistic Density
Computed constant air density that would have the same total effect on a projectile during its flight as the varying densities actually encountered.
Ballistic Efficiency
Ability of a projectile to overcome the resistance of the air. Ballistic efficiency depends chiefly on the weight, diameter and shape of the projectile.
Ballistic Limit
Velocity at which a given type of projectile will perforate a given thickness and type of armor plate at a specified obliquity.
Ballistic Mortar
Instrument used to determine the relative energy obtainable from explosive materials.
Ballistic Pendulum
An instrument used for measuring the velocity of a projectile or the output of a cartridge or explosive charge. Ballistic Rating
Ballistic Temperature
A computed constant temperature that would have the same total effect on a projectile traveling from the gun to the target as the varying temperatures actually encountered.
Ballistic Wave
Audible disturbance or wave caused by the compression of air ahead of a projectile in flight.
Ballistic Wind
Assumed constant wind that would have the same total effect on a projectile traveling from the gun to the target as the varying winds actually encountered.
Ballistics
The science of the motion of projectiles.
Ballistite
Smokeless powder used as a propelling charge in small arms and mortar ammunition.
Balloting
The bounding from side to side of a projectile in the bore of a gun.
Bandoleer
A wide ribbon of fabric or plastic provided with numerous adjoining pockets to accommodate small arms ammunition or similarly shaped items.
Bar
Derived from the Greek word “heavy”. A bar is a measure of pressure, one bar is equal to 0.9869 atmospheres or 105 pascals.
KBar
Kilobar = 1,000 Bars or 103 Bars
MBar
Megabar = 1,000,000 Bars or 106 Bars
Barium
Barium, a metallic element, isolated by electrolysis in 1808 by Sir Humphrey Davy. It is a soft, silver-white Alkaline-Earth Metal. Its principal ore is barite. Various barium compounds are used as paint pigments, rat poison, a drying agent, and a water softener, and in pyrotechnics. Element ; Periodic Table.
Barrage
A barrier of fire from guns, etc.
Bases & Acids
Acids & Bases.
Baseline Ejection Shell
Type of special purpose shell which functions by expelling its filler out of base of the shell. Expulsion is usually achieved by a small charge of propellant, called an expelling charge.
Base Line
Line of known length and direction between two points whose locations are known; used in fire control.
Base Plug
Seal in base of projectile.
Base Of Trajectory
Straight horizontal line from the center of the muzzle of a weapon to the point of intersection with the downward curve of the path of a projectile.
Base Spray
Spray.
Battery Actuation Cartridge
May be electric, percussion or pneumatic: A controlled pressure cartridge used to force electrolyte into a dry-charge battery. Pressure Cartridge.
Beam
A ray or collection of focused rays of radiated energy. Radio waves used as a navigation aid.
Beam Collapse Mechanism
A method of allowing a bridge to collapse under its own weight.
Benzene
Benzene (C6H6), colorless, flammable toxic liquid with a pleasant aromatic odor. A Hydrocarbon, benzene is the parent substance of the Aromatic Compounds. It consists of an unusually stable hexagonal ring of six carbon atoms, each of which is attached to a hydrogen atom. Derivative compounds include toluene, phenol, and aniline. Obtained from coal tar and petroleum, benzene and its derivatives are used in making dyes, drugs, and plastics.
Beryllium
Beryllium, a metallic element, first isolated in 1828 independently by Friedrich Wohler and Antoine Bussy. The silver-gray, Alkaline-Earth Metal is light, strong, high-melting, and resistant to corrosion. It is used as a window material for X-ray tubes and as a shield and a moderator in nuclear reactors. Element ; Periodic Table.
Binary Explosive
A two component explosive based on safe-to-handle compounds such as hydrazine or nitromethane, shipped separately and united at the site to form a high-energy explosive.
Binder
Compositions that hold together a charge of finely divided particles and increase the mechanical strength of plugs or pellets of these particles when consolidated under pressure. Binders usually are resins, plastics, asphaltics or hard waxes used dry or in solution.
Biological Agent
Viruses, any of certain classifications of microorganisms and toxic substance derived from living organisms used to produce death or disease in man, animals and growing plants.
Biological Warfare
Tactics and techniques of conducting warfare by use of biological agents.
Black Powder
A deflagrating or low explosive compound, consisting of a mixture of an alkali nitrate, usually potassium or sodium nitrate, mixed with charcoal and sulfur, which is mostly pressed, granulated and classified into definite grain fractions. It is easily ignited, friction sensitive, and produces dense smoke. Formerly used as a propellant before the advent of so-called smokeless powder; few remaining military uses, such as igniters, in fuzes to give short delay, in blank ammunition and as spotting charges. It deflagrates faster than it detonates; and is thus classified as a low explosive. The standard composition is: 75% potassium nitrate, 10% sulfur and 15% charcoal. There are also graded compositions containing 74, 70, 68 or 64% potassium nitrate. Corresponding compositions based on sodium nitrate are known as B-Black Powder.
Blank Ammunition
Ammunition containing no projectile but which does contain a charge of low explosive, such as black powder, to produce a noise; used in training, in signaling and in firing salutes.
Blast
Sudden air pressure created by the discharge of a gun or the explosion of a charge.
Blast Cube
Angle iron frame covered with aluminum sheets; used for testing effectiveness of blast.
Blast Shield
This is a specialty type of portable protective shield used by both bomb technicians and tactical personnel which is designed to protect the user from fragments, thermal effects and overpressure.
Blast Tube
Device used for the study of shock waves and for calibration of air-blast gages. Shock Tube.
Blaster
Shot Firer.
Blasting Accessories
Nonexplosive devices and materials used in blasting, such as, but not limited to, cap crimpers, tamping bags, blasting machines, blasting galvanometers, and cartridge punches.
Blasting Agent
Any material or mixture consisting of a fuel (combustible) and oxidizer, intended for blasting, not otherwise classified as an explosive provided that the finished product, as mixed and packaged for shipment, cannot be detonated by a commercial grade No. 8 blasting cap.
Blasting Cap
A small thin-walled cylindrical case containing a sensitive explosive. Also called a Detonator. Blasting caps serve as initiators of explosive charges. They consist of a cylindrical copper or aluminum capsule containing a primary charge of an initiating explosive or a mixture of initiating explosives (e.g. lead azide with lead trinitroresorcinate); in order to achieve a higher brisance, they also contain a secondary charge of a high brisance explosive (e.g. Tetryl; PETN; Cyclonite).
A blasting cap can be ignited by the flame of a safety fuse or electrically, or nonelectrically (as in the case of Shock Tube. In the past, 10 standard types of blasting caps were marketed; these differed from each other by the quantity of the explosive in the charge and by their size. Currently, No. 8 blasting cap (0.3 g primary charge. 0.8 g secondary charge, 4-50mm in length and 7.0 mm in external diameter) is, for all practical purposes, the main type of blasting cap on the market.
Blasting Galvanometer
An electrical resistance instrument designed specifically for testing electric detonators and circuits containing them. Along with blasting ohmmeters and blaster’s multimeters, it is used to measure resistance or to check electrical continuity.
Blasting Log
A written record of information about a specific blast as may be required by law or regulation.
Blasting Machine
An electrical or electromechanical device that provides electrical energy for the purpose of energizing detonators in an electric blasting circuit.
Blasting Machine - CD type
Capacitor-Discharge Blasting Machine.
Blasting Machine - Generator type
A hand-operated electromechanical device that provides an output current to energize electric detonators.
Blasting Machine Rheostat
A graduated electrical resistance device used to simulate electric detonator resistances in the testing of blasting machines.
Block Demolition Charge
Prepackaged, high explosive charges for general demolition operations, such as tree cutting, breaching and cratering; composed of a high explosive such as TNT, Tetrytol, Composition-C Series and / or Ammonium Nitrate.
Block-Hole Method
A way of removing boulders; a hole is drilled in the top of the boulder deep and wide enough to hold the required amount of explosive.
Blowback
Escape, to the rear and under pressure, of gases formed during the firing of a gun. Blowback may be caused by a defective breech mechanism, a ruptured cartridge, or a faulty primer.
Blow-out Disk
(Safety Diaphragm) A thin metal diaphragm used as a safety measure against excess gas pressure.
Boat-tail
Rear end of a projectile that is tapered or cone-shaped and not cylindrical, as in a projectile having a square base.
Boiling Point
Boiling point, the temperature at which a substance boils, or changes from a liquid to a vapor or gas ( States Of Matter), through the formation and rise to the surface of bubbles of vapor within the liquid. In a stricter sense, the boiling point of a liquid is the temperature at which its vapor pressure is equal to the local atmospheric pressure. Decreasing (or increasing) the pressure of the surrounding gases thus lowers (or raises) the boiling point of a liquid. The quantity of heat necessary to change 1 g of any substance from liquid to gas at its boiling point is known as its latent heat of vaporization.
Bomb
A criminal bomb is an explosive substance which is placed, dropped, thrown or projected with the unlawful intention of causing either injury, death, or destruction of property, or creating a disturbance.
Bomb Disrupter
A device which projects a fluid projectile or solid slug into an explosive package such as an I.E.D. or bomb. The intent is to decrease the density of the explosive by causing it to be spread apart from the impact of the projectile - at a speed which will be faster than the reaction time of the initiating system.
Bomb Suit
A protective suit worn by E.O.D personnel and bomb technicians when handling hazardous devices. The suit is specially designed and built to provide maximum protection to the wearer against fragments, thermal effects, overpressure and impact, which may result if a hazardous device is initiated.
Boom Powder
A pyrotechnic ignition mixture designed to produce many incandescent particles. A typical boom composition is:
Ingredient Parts By Weight
Iron Oxide 50
Titanium (Powdered) 32.5
Zirconium (Powdered) 17.5
plus about 1 part cellulose nitrate as a binder 
Booster
1) An explosive of special character, usually high strength and high detonating velocity, generally used in small quantities to improve the performance of another explosive, the latter constituting the major portion of the charge and normally a less sensitive explosive. When it is armed with a detonator, becomes a primer.
2) In rocketry, an auxiliary propulsion system employed in the early launching phase of a rocket vehicle or missile to attain the required speed.
Booster Charge
The final high explosive component of an explosive train which amplifies the detonation from the lead or detonator so as to reliably detonate the main high explosive charge. Also used loosely to indicate a reinforcing or augmenting charge.
Borax
Borax is sodium tetraborate decahydrate, the chemical compound (Na2B4O7 •10H2O) occurring as a colorless, crystalline salt or a white powder. Borax is used as an antiseptic, cleansing agent, water softener, corrosion inhibitor in antifreeze, and flux for silver soldering, and in the manufacture of fertilizers, Pyrex glass, and pharmaceuticals.
Bore
The cylindrical, and usually rifled, portion of the gun tube, or barrel interior, extending from the forcing cone to the muzzle. Bore is used both for the inside surface of the barrel or tube of a gun, with its rifling, and for the cylindrical space enclosed by that portion of the tube.
Bore Impression
Impression of the bore of a gun tube, made with a plastic substance in order to determine the condition of the rifling.
Bore Premature
The explosion of a gun-launched projectile in the barrel.
Boresafe Fuze
Type of fuse having an interrupter in the explosive train that prevents a functioning until after the projectile has cleared the muzzle of a weapon.
Bottom Attack
Forms a hinge at the top of the span being demolished; as the span falls, the cut ends at the bottom move outward.
Bourrelet
Finely machined band or ring of metal just behind the ogive of a projectile, designed to support the front portion of the projectile by riding the lands as the projectile travels through the bore of a gun.
Bow Wave
Ballistic Wave.
Branch Line
A length of detonating cord.
Breach Point
Access point to the target area.
Breaching Charges
Used to destroy concrete-slab bridges, bridge beams, bridge piers, bridge abutments, and permanent field fortifications. The size, shape, placement, and tamping or confinement of breaching charges are critical to success.
Breaching Device
A device designed to facilitate breaching activities. This may include explosive devices and mechanical devices.
Breaching Radius
(R) For external charges, it is equal to the thickness of the target being breached. For internal charges placed at the center of the targets mass, R is one half the thickness of the target. For internal charges placed less than one half the target mass thickness, R is the longer of the distances from the center of the charge to the outside of the target.
Breech
The rear part of the bore of a gun, especially the opening that permits the projectile to be inserted at the rear of the bore.
Breech-blast
Back-blast.
Breech Block
Movable steel block that closes the rear part of the barrel in a firearm.
Bridgewire
A relatively fine resistance wire incorporated into an ignition element connecting the ends of the legwires inside an electric detonator and which is imbedded in the ignition charge of the detonator.
Bridge Waves
Mach waves caused by the interaction of two shock waves to form a third that bridges the volume between the original two.
Brisance
The performance of an explosive cannot be expressed by means of a single characteristic parameter. Brisance is the destructive fragmentation effect of a charge on its immediate vicinity. The relevant parameters are the detonation rate and the loading density (compactness) of the explosive, as well as the gas yield and the heat of explosion. The higher the loading density of the explosive (molding or pressing density), the higher its performance concentration per unit volume; also, the faster the reaction rate, the stronger the impact effect of the detonation. Moreover, an increase in density is accompanied by an increase in the detonation rate of the explosive, while the shock wave pressure in the detonation front ( Detonation) varies with the square of the detonation rate. Thus it is very important to have the loading density as high as possible. This is particularly true for Shaped Charges.
Kast introduced the concept of “brisance value”, which is the product of loading density, specific energy and detonation rate. Brisance tests are upsetting tests according to Kast and HeB; the compression of a copper cylinder is determined by actuating a piston instrument; alternatively, a free-standing lead cylinder is compressed by the application of a definite cylindrical load of the explosive being tested: Upsetting Tests.
Brisant
Sudden, sharp, violent. A descriptive term which, when applied to explosions, indicates a powerful impulse of short duration.
British Thermal Unit
British thermal unit (BTU), unit of energy required to raise the temperature of 1 lb of water by one degree Fahrenheit (from 59.5° to 60.5°F). 1 BTU = 251.996 calories = 778.26 foot-pounds = 1054.8 joules.
Broadcasting
The transmission of sound or images to a number of Radio or Television receivers.
Bruceton Analysis
A statistical analysis approach to the problem of determining as economically as possible the behavior characteristics of explosive components by using a limited number of samples to determine a reliability factor. In this test, the level of variable applied depends upon the results of the previous test.
Buffer
A solution that can keep its pH, i.e., its relative acidity or alkalinity, constant despite the addition of strong acids or bases ( Acids & Bases). Buffer solutions contain either a weak acid or weak base and one of their salts. pH.
Bulk Density
The mass per unit volume of bulk materials. Used in connection with packaging, storage or transportation.
Bulk Strength
The strength per unit volume of an explosive calculated from its weight strength and density. Strength.
Bullet-Resistant
Magazine walls or doors of construction resistant to penetration of a bullet of 150-grain M2 ball ammunition having a nominal muzzle velocity of 2,700 ft/sec fired from a .30-caliber rifle from a distance of 100 ft perpendicular to the wall or door. When a magazine ceiling or roof is required to be bullet-resistant, the ceiling or roof shall be constructed of materials comparable to the sidewalls or other materials that will withstand penetration of the bullet described above when fired at an angle of 45 degrees from the perpendicular. Tests to determine bullet resistance should be conducted on test panels or empty magazines that will resist penetration of 5 out of 5 shots placed independently of each other in an area at least 3 ft. x 3 ft.
Bureau Of Mines Test
A U.S. Bureau Of Mines test for determination of the impact sensitivity of an explosive. A small sample of the explosive is placed between two hardened steel plates and a weight is dropped upon the upper plate. The figure representing the lowest height in centimeters at which at least one of ten trials results in explosion is the sensitivity index. The highest drop provided is 100 cm, so sensitivity may be given at 100+, meaning that at 100 cm, no explosion resulted.
Burning
(of propellant) Linear Burning Rate.
Burst
Explosion of a projectile in the air, or when it strikes the ground or target.
Burster
Explosive charge used to break open and spread the contents of chemical projectiles, bombs or mines.
Burster Tube
Tube that holds the burster in a chemical projectile.
Bursting Charge
Quantity of an explosive which breaks the casing of a projectile to produce demolition, fragmentation or chemical action.
Bus Wire
Expendable heavy-gauge bare copper wire used to connect detonators or series of detonators in parallel.

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