Smokeless powder
Encyclopedia
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
s used in firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...
s and artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
which produce negligible
Negligible
Negligible refers to the quantities so small that they can be ignored when studying the larger effect. Although related to the more mathematical concepts of infinitesimal, the idea of negligibility is particularly useful in practical disciplines like physics, chemistry, mechanical and electronic...
smoke when fired, unlike the older gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
(black powder) which they replaced. The basis of the term smokeless is that the combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
products are mainly gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
eous, compared to around 55% solid products (mostly potassium carbonate
Potassium carbonate
Potassium carbonate is a white salt, soluble in water , which forms a strongly alkaline solution. It can be made as the product of potassium hydroxide's absorbent reaction with carbon dioxide. It is deliquescent, often appearing a damp or wet solid...
, potassium sulfate
Potassium sulfate
Potassium sulfate is a non-flammable white crystalline salt which is soluble in water...
, and potassium sulfide
Potassium sulfide
Potassium sulfide is the inorganic compound with the formula K2S. The colourless solid is rarely encountered, because it reacts readily with water, a reaction that affords potassium bisulfide and potassium hydroxide .-Structure:...
) for black powder. Despite its name, smokeless powder is not completely smoke
Smoke
Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...
-free.
Since the 14th century gunpowder was not actually a physical "powder
Powder (substance)
A powder is a dry,thick bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material...
," and smokeless powder can only be produced as a pelletized
Pelletizing
Pelletizing is the process of compressing or molding a material into the shape of a pellet. A wide range of different materials are pelletized including chemicals, iron ore, animal compound feed, and more.- Pelletizing of iron ore :...
or extruded granular material
Granular material
A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact . The constituents that compose granular material must be large enough such that they are not subject to thermal motion fluctuations...
. Smokeless powder allowed the development of modern semi- and fully automatic firearms. Burnt black powder leaves a thick, heavy fouling
Fouling
Fouling refers to the accumulation of unwanted material on solid surfaces, most often in an aquatic environment. The fouling material can consist of either living organisms or a non-living substance...
which is hygroscopic and causes rusting of the barrel. The fouling left by smokeless powder exhibits none of these properties. This makes an autoloading firearm with many moving parts feasible (which would otherwise jam or seize under heavy black powder fouling).
Smokeless powders are classified as, typically, division 1.3 explosives under the UN Recommendations on the transportation of Dangerous goods
Dangerous goods
Dangerous goods are solids, liquids, or gases that can harm people, other living organisms, property, or the environment. They are often subject to chemical regulations. "HazMat teams" are personnel specially trained to handle dangerous goods...
- Model Regulations, regional regulations (such as ADR
European Agreement concerning the International Carriage of Dangerous Goods by Road
The European Agreement concerning the International Carriage of Dangerous Goods by Road, commonly known as ADR , governs transnational transport of hazardous materials.Launched in Geneva on 30 September 1957 under the aegis of the United...
) and national regulations (such the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
' ATF
Bureau of Alcohol, Tobacco, Firearms and Explosives
The Bureau of Alcohol, Tobacco, Firearms and Explosives is a federal law enforcement organization within the United States Department of Justice...
). However, they are used as solid propellants; in normal use, they undergo deflagration
Deflagration
Deflagration is a term describing subsonic combustion that usually propagates through thermal conductivity; hot burning material heats the next layer of cold material and ignites it. Most "fire" found in daily life, from flames to explosions, is deflagration...
rather than detonation
Detonation
Detonation involves a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations are observed in both conventional solid and liquid explosives, as well as in reactive gases...
.
Background
Military commanders had been complaining since the Napoleonic WarsNapoleonic Wars
The Napoleonic Wars were a series of wars declared against Napoleon's French Empire by opposing coalitions that ran from 1803 to 1815. As a continuation of the wars sparked by the French Revolution of 1789, they revolutionised European armies and played out on an unprecedented scale, mainly due to...
about the problems of giving orders on a gunnery battlefield. Verbal commands could not be heard above the noise of the guns, and visual signals could not be seen through the thick smoke from the gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
used by the guns. Unless there was a strong wind, after a few shots, soldiers using black powder ammunition would have their view obscured by a huge cloud of smoke. Sniper
Sniper
A sniper is a marksman who shoots targets from concealed positions or distances exceeding the capabilities of regular personnel. Snipers typically have specialized training and distinct high-precision rifles....
s or other concealed shooters were given away by a cloud of smoke over the firing position. Black powder is also corrosive, making cleaning mandatory after every use. Likewise, black powder's tendency to produce severe fouling caused actions to jam and often made reloading difficult.
A major step forward was the discovery of guncotton, a nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
-based material, by Christian Friedrich Schönbein
Christian Friedrich Schönbein
Christian Friedrich Schönbein was a German-Swiss chemist who is best known for inventing the fuel cell and his discoveries of guncotton and ozone.- Life :...
in 1846. He also promoted its use as a blasting explosive. Guncotton was more powerful than gunpowder, but at the same time was somewhat more unstable. This made it unsuitable as a propellant for small firearms: not only was it dangerous under field conditions, but guns that could fire thousands of rounds using gunpowder would reach their service life after only a few hundred with the more powerful guncotton. It did find wide use with artillery. However, within a short time there were a number of massive explosions and fatalities in guncotton factories due to lack of appreciation of its sensitivity and the means of stabilization. Guncotton then went out of use for some twenty years or more until it could be tamed; it was not until the 1880s that it became a viable propellant.
19th century improvements
In 1884, Paul Vieille invented a smokeless gunpowder called Poudre BPoudre B
Poudre B : was the first practical smokeless gunpowder. Originally called "Poudre V" from the name of the inventor, Paul Vieille, it was later renamed "Poudre B" to distract German espionage...
, made from collodion
Collodion
Collodion is a flammable, syrupy solution of pyroxylin in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...
(nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
gelatinized with ether
Diethyl ether
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...
and alcohol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
). It was passed through rollers to form paper thin sheets, which were cut into flakes of the desired size. The resulting propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
, today known as pyrocellulose, contains somewhat less nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
than guncotton and is less volatile. A particularly good feature of the propellant is that it will not detonate unless it is compressed, making it very safe to handle under normal conditions.
Vieille's powder revolutionized the effectiveness of small guns, because it gave off almost no smoke and was three times more powerful than black powder. Higher muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
meant a flatter trajectory
Trajectory
A trajectory is the path that a moving object follows through space as a function of time. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit—the path of a planet, an asteroid or a comet as it travels around a central mass...
and less wind drift and bullet drop, making 1000 meter shots practicable. Since less powder was needed to propel a bullet, the cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...
could be made smaller and lighter. This allowed troops to carry more ammunition for the same weight. Also, it would burn even when wet. Black powder ammunition had to be kept dry and was almost always stored and transported in watertight cartridges.
Vielle's powder was used in the Lebel rifle that was immediately introduced by the French Army
Military of France
The French Armed Forces encompass the French Army, the French Navy, the French Air Force and the National Gendarmerie. The President of the Republic heads the armed forces, with the title "chef des armées" . The President is the supreme authority for military matters and is the sole official who...
to exploit its huge benefits over black powder. Other European countries swiftly followed and started using their own versions of Poudre B, the first being Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
and Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
which introduced new weapons in 1888.
Meanwhile, in 1887, Alfred Nobel
Alfred Nobel
Alfred Bernhard Nobel was a Swedish chemist, engineer, innovator, and armaments manufacturer. He is the inventor of dynamite. Nobel also owned Bofors, which he had redirected from its previous role as primarily an iron and steel producer to a major manufacturer of cannon and other armaments...
developed a smokeless gunpowder called Ballistite
Ballistite
Ballistite is a smokeless propellant made from two high explosives, nitrocellulose and nitroglycerine. It was developed and patented by Alfred Nobel in the late 19th century.-The development of smokeless powders:...
. A modified form of this was devised by Sir Frederick Abel and James Dewar
James Dewar
Sir James Dewar FRS was a Scottish chemist and physicist. He is probably best-known today for his invention of the Dewar flask, which he used in conjunction with extensive research into the liquefaction of gases...
which eventually became known as Cordite
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...
, leading to a lengthy court battle between Nobel and the other two inventors over alleged British patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
infringement. In the USA, in 1890, a patent for smokeless powder was obtained by Hudson Maxim
Hudson Maxim
Hudson Maxim , was a U.S. inventor and chemist who invented a variety of explosives, including smokeless gunpowder. He was the brother of Hiram Stevens Maxim, inventor of the Maxim gun and uncle of Hiram Percy Maxim, inventor of the Maxim Silencer.Maxim was a man of many talents...
.
Chemical variations
These newer propellants were more stable and thus safer to handle than Poudre B, and also more powerful. Today, propellants based on nitrocellulose alone (typically an ether-alcohol colloid of nitrocellulose) are described as single-base powder, whereas cordite-like mixtures using nitroglycerin to dissolve the nitrocellulose are known as double-base powder. Single and double-base smokeless powders now make up the vast majority of propellants used in firearms. A triple-base powder including nitroguanidineNitroguanidine
Nitroguanidine is a chemical compound. It is a colorless, crystalline solid. It melts at 232 °C and decomposes at 250 °C. It is not flammable and is an extremely low sensitivity explosive; however, its detonation velocity is high.-Manufacture:...
was developed as a flashless cordite primarily for large naval guns
Naval artillery
Naval artillery, or naval riflery, is artillery mounted on a warship for use in naval warfare. Naval artillery has historically been used to engage either other ships, or targets on land; in the latter role it is currently termed naval gunfire fire support...
, but also used in battle tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
ammunition.
Instability and stabilization
Nitrocellulose deteriorates with time, yielding acidic byproducts. Those byproducts catalyze the further deterioration, increasing its rate. The released heat, in case of bulk storage of the powder, or too large blocks of solid propellant, can cause self-ignition of the material. Single-base nitrocellulose propellants are most susceptible to degradation; double-base and triple-base propellants tend to deteriorate more slowly. To neutralize the decomposition products, which could otherwise cause corrosion of metals of the cartridges and gun barrels, calcium carbonateCalcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
is added to some formulations.
To prevent buildup of the deterioration products, stabilizers
Stabilizer (chemistry)
In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym to a catalyst...
are added. Diphenylamine
Diphenylamine
Diphenylamine is the organic compound with the formula 2NH. It is a colourless solid, but samples are often yellow due to oxidized impurities.-Preparation and reactivity:...
is one of the most common stabilizers used. Nitrated analogs of diphenylamine formed in the process of stabilizing decomposing powder are sometimes used as stabilizers themselves. The stabilizers are added in the amount of 0.5-2% of the total amount of the formulation; higher amounts tend to degrade its ballistic properties. The amount of the stabilizer is depleted with time. Propellants in storage should be periodically tested for the amount of stabilizer remaining, as its depletion may lead to auto-ignition of the propellant.
Physical variations
Extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
into cylinders or flakes using solvents such as ether. The properties of the propellant are greatly influenced by the size and shape of its grains. The specific surface area of the propellant influences the speed of burning, and the size and shape of the particles determine the specific surface area. By manipulation of the grain shape it is possible to influence the ignition rate and hence the rate at which pressure builds during combustion. Smokeless powder burns only on the surfaces of the granules, flakes or cylinders (described as granules for short). Larger granules burn more slowly, and the burn rate is further controlled by flame-deterrent coatings which retard burning slightly. The intent is to regulate the burn rate so that a more or less constant pressure is exerted on the propelled projectile as long as it is in the barrel so as to obtain the highest velocity. Cannon
Cannon
A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellents to launch a projectile. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees,...
powder has the largest granules, up to thumb-sized cylinders with seven perforations (one central and the other six in a circle halfway to the outside of the cylinder's end faces). The perforations stabilize the burn rate because as the outside burns inward (thus shrinking the burning surface area) the inside is burning outward (thus increasing the burning surface area, but faster, so as to fill up the increasing volume of barrel presented by the departing projectile). Fast-burning pistol
Pistol
When distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...
powders are made by extruding shapes with more area such as flakes or by flattening the spherical granules. Drying is usually performed under a vacuum. The solvents are condensed and recycled. The granules are also coated with graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
to prevent static electricity sparks from causing undesired ignitions.
Faster-burning propellants generate higher temperatures and higher pressures, however they also increase wear on gun barrels.
Smokeless propellant components
The propellant formulations may contain various energetic and auxiliary components:- Propellants:
- NitrocelluloseNitrocelluloseNitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
, an energetic component of most smokeless propellants - Nitroglycerin, an energetic component of double-base and triple-base formulations
- NitroguanidineNitroguanidineNitroguanidine is a chemical compound. It is a colorless, crystalline solid. It melts at 232 °C and decomposes at 250 °C. It is not flammable and is an extremely low sensitivity explosive; however, its detonation velocity is high.-Manufacture:...
, a component of triple-base formulations - D1NA (bis-nitroxyethylnitramine)
- Fivonite (tetramethylolcyclopentanone)
- DGN (di-ethylene glycol dinitrate)
- Acetyl cellulose
- Nitrocellulose
- Deterrents, (or moderants), to slow the burning rate
- CentraliteCentraliteCentralite is a gunshot residue also known as ethyl centralite. Its IUPAC name is 1,3-diethyl-1,3-diphenylurea. Ethyl centralite is insoluble in water, but is soluble in acetone, ethanol and benzene...
s (symmetrical diphenyl urea -- primarily diethyl or dimethyl) - Dibutyl phthalateDibutyl phthalateDibutyl phthalate is a commonly used plasticizer. It is also used as an additive to adhesives or printing inks. It is soluble in various organic solvents, e.g. in alcohol, ether and benzene...
- DinitrotolueneDinitrotoluene2,4-Dinitrotoluene or Dinitro is an organic compound with the formula C6H32. This pale yellow crystalline solid is well known as a precursor to trinitrotoluene but is mainly used in the polymer industry....
(toxic, carcinogenic, and obsolete) - Akardite (asymmetrical diphenyl urea)
- ortho-tolyl urethane
- Polyester adipate
- CamphorCamphorCamphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel , a large evergreen tree found in Asia and also of Dryobalanops aromatica, a giant of the Bornean forests...
(obsolete)
- Centralite
- StabilizersStabilizer (chemistry)In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym to a catalyst...
, to prevent or slow down self-decomposition- DiphenylamineDiphenylamineDiphenylamine is the organic compound with the formula 2NH. It is a colourless solid, but samples are often yellow due to oxidized impurities.-Preparation and reactivity:...
- Petroleum jellyPetroleum jellyPetroleum jelly, petrolatum, white petrolatum or soft paraffin, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons , originally promoted as a topical ointment for its healing properties...
- Calcium carbonateCalcium carbonateCalcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
- Magnesium oxideMagnesium oxideMagnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...
- Sodium bicarbonateSodium bicarbonateSodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
- beta-naphthol methyl ether
- Amyl alcoholAmyl alcoholAn amyl alcohol is any of 8 alcohols with the formula C5H11OH. A mixture of amyl alcohols can be obtained from fusel alcohol. Amyl alcohol is used as a solvent and in esterfication for example in the production of amyl acetate...
(obsolete) - AnilineAnilineAniline, phenylamine or aminobenzene is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Being a precursor to many industrial chemicals, its main use is in the manufacture of precursors to polyurethane...
(obsolete)
- Diphenylamine
- DecopperingDecopperingDecoppering is the act of removing copper and it is most commonly used in the context of the removal of copper residues from the rifling of gun barrels.Decoppering agents are frequently added to smokeless powder propellants...
additives, to hinder the buildup of copper residues from the gun barrel rifling- TinTinTin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
metal and compounds (e.g., tin dioxideTin dioxideTin dioxide is the inorganic compound with the formula SnO2. The mineral form of SnO2 is called cassiterite, and this is the main ore of tin. With many other names , this oxide of tin is the most important raw material in tin chemistry...
) - BismuthBismuthBismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
metal and compounds (e.g., bismuth trioxideBismuth trioxideBismuth oxide is perhaps the most industrially important compound of bismuth. It is also a common starting point for bismuth chemistry. It is found naturally as the mineral bismite and sphaerobismoite , but it is usually obtained as a by-product of the smelting of copper and lead ores...
, bismuth subcarbonateBismuth subcarbonateBismuth subcarbonate Bi2O2, sometimes written 2CO3 is a chemical compound of bismuth containing both oxide and carbonate anions. Bismuth is in the +3 oxidation state. Bismuth subcarbonate occurs naturally as the mineral bismutite. Its structure consists of Bi-O layers and CO3 layers and is related...
, bismuth nitrate, bismuth antimonide); the bismuth compounds are favored as copper dissolves in molten bismuth, forming brittle and easily removable alloy - LeadLeadLead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
foil and lead compounds, phased out due to toxicity
- Tin
- Flash reducers, to reduce the brightness of the muzzle flashMuzzle flashMuzzle blast is the term used to describe the release of high temperature, high pressure gases expelled from the muzzle of a firearm when it is discharged. Muzzle flash is the term used to describe the visible light of the muzzle blast. The blast and flash are caused by the combustion products of...
(all have a disadvantage: the production of smoke)- Potassium chloridePotassium chlorideThe chemical compound potassium chloride is a metal halide salt composed of potassium and chlorine. In its pure state, it is odorless and has a white or colorless vitreous crystal appearance, with a crystal structure that cleaves easily in three directions. Potassium chloride crystals are...
- Potassium nitratePotassium nitratePotassium nitrate is a chemical compound with the formula KNO3. It is an ionic salt of potassium ions K+ and nitrate ions NO3−.It occurs as a mineral niter and is a natural solid source of nitrogen. Its common names include saltpetre , from medieval Latin sal petræ: "stone salt" or possibly "Salt...
- Potassium sulfatePotassium sulfatePotassium sulfate is a non-flammable white crystalline salt which is soluble in water...
- Potassium hydrogen tartarate (a byproduct of wine production formerly used by French artillery)
- Potassium chloride
- Wear reduction additives, to lower the wear of the gun barrel liners
- WaxWaxthumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...
- TalcTalcTalc is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg34 or Mg3Si4O102. In loose form, it is the widely-used substance known as talcum powder. It occurs as foliated to fibrous masses, its crystals being so rare as to be almost unknown...
- Titanium dioxideTitanium dioxideTitanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
- PolyurethanePolyurethaneA polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
jackets over the powder bags, in large guns
- Wax
- Other additives
- Ethyl acetateEthyl acetateEthyl acetate is the organic compound with the formula CH3COOCH2CH3. This colorless liquid has a characteristic sweet smell and is used in glues, nail polish removers, and cigarettes...
, a solvent for manufacture of spherical powder - RosinRosin.Rosin, also called colophony or Greek pitch , is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black...
, a surfactant to hold the grain shape of spherical powder - GraphiteGraphiteThe mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
, a lubricantLubricantA lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...
to cover the grains and prevent them from sticking together, and to dissipate static electricityStatic electricityStatic electricity refers to the build-up of electric charge on the surface of objects. The static charges remain on an object until they either bleed off to ground or are quickly neutralized by a discharge. Static electricity can be contrasted with current electricity, which can be delivered...
- Ethyl acetate
Manufacturing
The United States NavyUnited States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
manufactured single-base tubular powder for naval artillery at Indian Head, Maryland
Indian Head, Maryland
Indian Head is a town in Charles County, Maryland, United States. The population was 3,422 at the 2000 census. It has been the site of a naval base specializing in gun and rocket propellants since 1890. Production of nitrocellulose and smokeless powder began at the Indian Head Powder Factory in 1900...
, beginning in 1900. Similar procedures were used for United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
production at Picatinny Arsenal
Picatinny Arsenal
The Picatinny Arsenal is an American military research and manufacturing facility located on a lot in northern New Jersey near Lake Denmark. The Arsenal is the headquarters of the United States Army Armament Research, Development and Engineering Center...
beginning in 1907 and for manufacture of smaller grained Improved Military Rifle (IMR)
Improved Military Rifle (IMR)
Improved Military Rifle describes a series of tubular nitrocellulose smokeless powders evolved from World War I through World War II for loading military and commercial ammunition and sold to private citizens for reloading rifle ammunition for hunting and target shooting...
powders after 1914. Short-fiber cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
linter was boiled in a solution of sodium hydroxide to remove vegetable waxes, and then dried before conversion to nitrocellulose by mixing with concentrated nitric
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
and sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
s. Nitrocellulose still resembles fibrous cotton at this point in the manufacturing process, and was typically identified as pyrocellulose because it would spontaneously ignite in air until unreacted acid was removed. The term guncotton was also used; although some references identify guncotton as a more extensively nitrated and refined product used in torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
and mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
warhead
Warhead
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.- Etymology :During the early development of naval torpedoes, they could be equipped with an inert payload that was intended for use during training, test firing and exercises. This...
s prior to use of TNT.
Unreacted acid was removed from pyrocellulose pulp by a multistage draining and water washing process similar to that used in paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
mills during production of chemical woodpulp. Pressurized alcohol removed remaining water from drained pyrocellulose prior to mixing with ether and diphenylamine. The mixture was then fed through a press extruding a long turbular cord form to be cut into grains of the desired length.
Alcohol and ether were then evaporated from "green" powder grains to a remaining solvent concentration between 3 percent for rifle powders and 7 percent for large artillery powder grains. Burning rate is inversely proportional to solvent concentration. Grains were coated with electrically conductive graphite to minimize generation of static electricity during subsequent blending. "Lots" containing more than ten tonnes of powder grains were mixed through a tower arrangement of blending hoppers to minimize ballistic differences. Each blended lot was then subjected to testing to determine the correct loading charge for the desired performance.
Military quantities of old smokeless powder were sometimes reworked into new lots of propellants. Through the 1920's Dr. Fred Olsen worked at Picatinny Arsenal experimenting with ways to salvage tons of single-base cannon powder manufactured for World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. Dr. Olsen was employed by Western Cartridge Company
Western Cartridge Company
The Western Cartridge Company manufactures small arms and ammunitions. Founded in 1898, it was the forerunner of the Olin Corporation, formed in 1944, of which Western is still a subsidiary, and is based in East Alton, Illinois, USA...
in 1929 and developed a process for manufacturing spherical smokeless powder by 1933. Reworked powder or washed pyrocellulose can be dissolved in ethyl acetate containing small quantities of desired stabilizers and other additives. The resultant syrup, combined with water and surfactant
Surfactant
Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...
s, can be heated and agitated in a pressurized container until the syrup forms an emulsion
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...
of small spherical globules of the desired size. Ethyl acetate distills off as pressure is slowly reduced to leave small spheres of nitrocellulose and additives. The spheres can be subsequently modified by adding nitroglycerine to increase energy, flattening between rollers to a uniform minimum dimension, coating with phthalate deterrents to retard ignition, and/or glazing with graphite to improve flow characteristics during blending.
Flashless powder
Nitrocellulose contains insufficient oxygen to completely oxidize its carbon and hydrogen. The oxygen deficit is increased by addition of graphite and organic stabilizers. Products of combustion within the gun barrel include flammable gasses like hydrogen and carbon monoxide. At high temperature, these flammable gasses will ignite when turbulently mixed with atmospheric oxygen beyond the muzzle of the gun. During night engagements the flash produced by ignition can reveal the location of the gun to enemy forces and cause temporary night-blindness among the gun crew by photo-bleaching visual purpleRhodopsin
Rhodopsin, also known as visual purple, is a biological pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light. Rhodopsins belong to the G-protein coupled receptor family and are extremely sensitive to light,...
. Flash suppressor
Flash suppressor
A flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle or other gun that reduces the visible signature of the burning gases that exit the muzzle. This reduces the chances that the shooter will be blinded in dark...
s are commonly used on small arms to reduce the flash signature, but this approach has been less successful for artillery. Artillery muzzle flash up to 150 feet (50 meters) from the muzzle has been observed, and can be reflected off clouds and be visible for distances up to 30 miles (50 kilometers).
Flash suppression was achieved by smokeless powder additives. Cooler burning explosives like nitroguanidine or ammonium nitrate were added to reduce the temperature of combustion gasses. Inorganic salts like potassium chloride were added so their specific heat capacity might reduce the temperature of combustion gasses and their finely divided particulate smoke might block visible wavelengths of radiant energy of combustion.
See also
- Antique gunsAntique gunsAn antique firearm is, loosely speaking, a firearm designed and manufactured prior to the beginning of the 20th century. The Boer War is often used as a cut-off event, although the exact definition of what constitutes an "antique firearm" varies from jurisdiction to jurisdiction...
- BallistiteBallistiteBallistite is a smokeless propellant made from two high explosives, nitrocellulose and nitroglycerine. It was developed and patented by Alfred Nobel in the late 19th century.-The development of smokeless powders:...
- CorditeCorditeCordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...
- Firearms
- GunpowderGunpowderGunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
- NitrocelluloseNitrocelluloseNitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
- Small armsSmall armsSmall arms is a term of art used by armed forces to denote infantry weapons an individual soldier may carry. The description is usually limited to revolvers, pistols, submachine guns, carbines, assault rifles, battle rifles, multiple barrel firearms, sniper rifles, squad automatic weapons, light...
- Brown-brownBrown-brownBrown-brown is a form of powdered cocaine mixed with smokeless gunpowder . Smokeless powder often contains nitroglycerine, a drug prescribed for heart conditions, which may help combat the negative cardiac side-effects of cocaine. Also it may refer to heroin...
– a drug created by mixing cocaine with cartridge powder
External links
- The Manufacture of Smokeless Powders and their Forensic Analysis: A Brief Review - Robert M. Heramb, Bruce R. McCord