by Wayne van Zwoll
Gunpowder dates to the 13th century. It’s cleaner, stronger, more efficient now. And more complex.
English friar and philosopher Roger Bacon described gunpowder in 1249 – a couple of centuries after the explosive “Chinese snow” appeared in fireworks. But Bacon’s compound was hardly a reliable propellant. The very idea of bottling gas pressure from burning powder to hurl a projectile from a barrel had yet to be explored. Not until the early 14th century would firearms appear in England, after Berthold Schwarz’s work on propulsion. In 1327 Edward II used guns as weapons during his invasion of Scotland.
Early gunpowder comprised roughly 40% saltpeter with equal proportions of charcoal and sulfur. In 1338 French chemists changed the composition to 50-25-25. The English later settled on a mix of 75-15-10. That recipe served until 1846, when guncotton appeared.
Black powder still comprises sulfur, charcoal and saltpeter. They’re ground fine and mixed at 3% moisture. The powder “meal” is pressed into cakes, which are fed through a granulating machine where toothed cylinders chop them. After screening to size, granules are polished in revolving wooden barrels. Most commonly, black powder is labeled, in decreasing order of granule size, A-1, Fg, Ffg, FFFg, FFFFg or FFFFFg. Bigger grains generally burn slowest and work best in big charges pushing heavy balls or bullets. Very fine black powder is limited for priming charges and pyrotechnics. Albeit most sportsmen know black powder as a traditional propellant for muzzle-loading rifles and early centerfire rounds, it still is used in detonating charges for high-energy artillery shells, and propels ejection seats clear of aircraft.
A mill at Milton, Massachusetts, near Boston, was probably the first U.S. powder manufacturing plant. By the beginning of the Revolution, enterprising colonists had amassed, by manufacture or capture, 40 tons of black powder! Half went to Cambridge, where it was wasted before George Washington took charge of the Revolutionary Army. Soon the Continental Army had no powder at all. New mills became a priority, and by war’s end American powder stocks had reached 1,000 tons. By 1800 our nation’s powder mills were producing 750 tons each year.
Black powder was easy to ignite in open air, not so easy in a chamber that bottled the expanding gas. The first guns, developed in Europe a century and a half before Columbus sailed for the New World, were heavy tubes that required two attendants. The Swiss called these firearms culverins. The culveriner held the tube, while his partner, lit a priming charge with a smoldering stick or rope. While culverins were clumsy and inaccurate and often misfired, the noise and smoke could rout an enemy armed with spears or even bows. Culverin muzzles were fitted with ax heads, to make them useful when ignition failed.
Such crude firearms were mostly fired at massed troops, not individual soldiers. Development of trigger mechanisms enabled the shooter to time a shot, rather than wait for a wick to burn into the charge at its leisure. Matchlock, wheellock and flintlock mechanisms followed. A common weakness: exposed priming powder. Moisture and wind could render the gun instantly useless. Also, a weak spark might fail to ignite even dry priming. If it did ignite, flame sometimes failed to reach the main charge, yielding only a “flash in the pan.” Generating spark inside the gun became possible early in the 18th century, with the discovery of fulminates. A blow released their energy immediately and more reliably than striking a flint. Adding saltpeter to fulminates of mercury produced a shock-sensitive but stable explosive: “Howard’s powder,” after Englishman E.C. Howard, who discovered it in 1799. This compound may have helped Scotch clergyman Alexander Forsythe became, in 1806, the first on record to ignite a spark inside a gun.
Forty years later, Italian Ascanio Subrero came up with a colorless liquid comprising nitric and sulphuric acids plus glycerin. Unlike ordinary black powder, nitroglycerine is not a blend of fuels and oxidants. It is instead an unstable, oxygen-rich compound that, with a jolt, can instantly rearrange itself into more stable gases. With age “nitro” can become more unstable. In 1863 Swedish chemist Emmanuel Nobel and son Alfred figured out how to put this frisky substance in cans, so it was easier to handle. Still, several shipments blew up. So did Nobel’s factory in Germany. Alfred later found that soaking the porous earth Kieselguhr with nitro rendered the chemical less sensitive. Dynamite followed, in 1875.
Meanwhile, in the 1840s, Swiss chemist Christian Schoenbein discovered that cotton treated with nitric and sulfuric acids formed a compound that burned so fast the fire would consume the cotton without igniting a heap of black powder on top! Schoenbein obtained an English patent for his work, then sold the procedure to Austria. Shortly, John Hall and Sons built a guncotton plant in Faversham, England. It blew up. So did most of the other guncotton plants built at the time. Chemists concluded this substance burned too fast and unpredictably for use as a propellant. Chlorate powders, pioneered by Berthollet in the 1780s, got the same reception. When a French powder plant at Essons blew up in 1788, potassium chlorate was deemed too sensitive for use in firearms.
Eventually bright people learned how to harness these compounds. In the 1850s J.J. Pohl came up with what he called “white powder.” It comprised 49% potassium chlorate, 28% yellow potash and 23% sulfur. A second-rate propellant, it served the Confederacy when black powder became scarce during the Civil War. Backyard powder mills turned out propellants of widely varying compositions and behaviors. One con artist hawked a potent mix of coffee, sugar, alum and potassium chlorate!
In 1869 Prussian immigrant Carl Dittmar built a plant to make “Dualin,” a nitro-treated sawdust. A year later he introduced his “New Sporting Powder.” By 1878 he was building a mill in Binghampton, New York. It blew, taking part of Binghampton with it. When Dittmar’s health failed, he sold what was left of his firm. One of his foreman, Milton Lindsey, landed at the King Powder Company, then worked with its president, G.M. Peters to develop “King’s Semi-Smokeless Powder,” patented in 1899. Dupont’s “Lesmoke” appeared soon thereafter, with roughly the same composition: 60% saltpeter, 20% cellulose, 12% charcoal, 8% sulfur. One of several semi-smokeless powders of that time, “Lesmoke” proved a fine propellant for .22 rimfires. Bore residue didn’t harden as did that of black powder. “Lesmoke” was more hazardous to produce than smokeless, however, and was discontinued in 1947.
French engineer Paul Vielle is generally credited with the first successful smokeless powder. But a decade earlier, Austrian chemist Frederick Volkmann had a cellulose-based powder. In 1875 Austrian patents proved inadequate protection for Volkmann’s work. When it was appropriated, he shuttered his plant, then vanished. By 1887 Alfred Nobel had boosted the nitrocellulose component in blasting gelatin and found it worked as a propellant. A year later he introduced “Ballistite.” Containing both nitrocellulose and nitroglycerin, this double-base powder resembled a mix developed concurrently by Hiram Maxim, of machine-gun fame. At the same time the British War Office came up with Cordite, with elements of both Nobel’s formula and Maxim’s. Named for a stage in manufacture, when paste squeezed through a die formed spaghetti-like cords, Cordite first comprised 58% nitroglycerine and 37% guncotton, later 30% nitroglycerine, 65% guncotton, plus mineral jelly and acetone. Nobel and Maxim unsuccessfully sued the British government for patent infringement.
Nitrated lignin gave early smokeless powders a lumpy or fuzzy appearance; bulk densities varied. Bulk powders could be substituted, by volume, for black powder. Dense or gelatin powders could not be safely measured by bulk, as their energy/volume ratios were higher. The shooting industry responded by marking shotgun loads in “drams equivalent.” In other words, the smokeless powder used gave the same performance as black-powder shotshells loaded with the marked number of drams. Handloaders charging rifle and pistol cases were cautioned to treat smokeless as a new fuel, with new rules.
In 1886 the 8mm Lebel, adopted by the French army, became the first military cartridge designed for smokeless powder. England followed with the .303 British in 1888, Switzerland the next year with the 7.5×55 Schmidt-Rubin. By the mid-1890s nearly all nations that could field an army were issuing small-bore bolt rifles firing smokeless cartridges. The new propellant boosted bullet speed by a third and didn’t give away a rifleman’s position with lingering clouds of spent saltpeter.
Oddly, most powder firms established in the 1890s failed. Fierce competition and flawed product, combined with the hazards of powder manufacture, made this a tough business. Mergers among powder firms were common. In 1890, Samuel Rodgers, an English physician living in San Francisco, formed the United States Powder Company to produce ammonium nitrate. Then he partnered with the Giant Powder Company to make “Gold Dust Powder,” comprising 55% ammonium picrate, 25% sodium or potassium nitrate, 20% ammonium bichromate. The Giant Powder Company plant blew up in 1898, while “Peyton Powder” by the California Powder Works fueled .30-40 Krag ammo for the U.S. Army. Laflin & Rand manufactured “W-A” double-base powder for the Krag (initials for developers Whistler and Aspinwall). W-A contained 30% nitroglycerin, which contributed to high burn temperatures and erosive tendencies.
The American Smokeless Powder Company, of New Jersey, produced under contract for the government until creditor Laflin & Rand acquired ASPC in 1898. Earlier, Laflin & Rand had sought American rights to Ballistite but rejected Nobel’s price of $300,000 plus royalties. Ballistite manufacture later came under the control of DuPont, which contracted that job to Laflin & Rand. Lightning, Unique, Sharpshooter and L&R Smokeless powders originated at Laflin & Rand.
The Robin Hood Powder Company of Vermont became the Robin Hood Ammunition Company before it sold in 1915 to the Union Metallic Cartridge Company. The American E.C. & Schultz Powder Company was acquired by DuPont in 1903, then became part of Hercules when DuPont was split by court order in 1912. Early nitrocellulose powders by DuPont and the California Powder Works fulfilled military contracts as early as 1897. They resembled Cordite. “Government Pyro” was among the first such powder to see military action, in .30-06 ammo. DuPont later fueled the ‘06 with #1147 and #1185, replacing them with IMR (Improved Military Rifle) 4895.
Even after Hercules fired up its modern powder plant in Kenville, New Jersey, DuPont dominated the market. It manufactured up to a ton of powder daily, and great quantities of dynamite. By the onset of World War I, Hercules had a factory in Parlin, New Jersey, there making nitrocellulose and popular rifle and pistol powders, including Bullseye, Infallible and HiVel. But DuPont got war contracts that profited its plants in Old Hickory, Tennessee and Nitro (really!), West Virginia. Combined capacity: 1.5 million pounds daily! After the war DuPont bought the town of Old Hickory to build a rayon factory. One day in August, 1924, the remaining powder magazines caught fire, incinerating more than 100 buildings and 50 million pounds of powder in a fearsome blaze.
During the Great War, Hercules manufactured up to 12,000 pounds of Cordite powder a day for the British government. Wartime Cordite production totaled 46 million pounds. In addition, Hercules sold 3 million pounds of small arms propellants and 54 million pounds of cannon powder. The conflict spurred improvements in powders. Plagued by copper residue fouling cannon bores, U.S. munitions experts took a tip from the French and added tin to their propellants. Soon rifle powders got the same treatment. With 4% tin DuPont’s No. 17 became No. 17 1/2. No. 15 became No. 15 1/2. Tin levels were halved when dark rings appeared in the bores of National Match rifles, a result of tin cooling near the muzzle.
These days, smokeless power for small arms starts out as nitrocellulose – vegetable fiber soaked in nitric and sulfuric acids. Guncotton has slightly higher nitrogen content (13.2% compared to 12.6%) and lower solubility in ether-alcohol solution. All nitrocellulose in powder production comes from short fibers or linters, which are boiled in caustic soda to remove oils. Water formed in nitrating is absorbed by the sulfuric acid, thus preventing decomposition by hydrolysis. A centrifuge next strips excess acid; then the linters are rinsed and boiled to remove all acid, which can cause spontaneous combustion. After more boiling, then beating and fluffing, the nitrocellulose is washed in solvent. Heating evaporates the solvent. Ether is used to dissolve fibers in nitrocellulose marked for single-base powders, acetone for double-base. Nitroglycerin is then added to the double-base propellants.
As the nascent powder becomes firmer, it is squeezed through dies (extruded) to form tubes that are pushed through a plate, where a whirling knife shears them into measured increments. The resulting grains of single-base powders still contain ether, so they’re sent to a warm solvent-recovery room, where they soak in water for a couple of weeks. Wet single-base and freshly sheared double-base powders are then air-dried, sieved and polished in drums that coat them with graphite. Tumbling smoothes edges that cause friction. Graphite further reduces friction and imparts color. Uncoated powder is yellow.
Extruded or “stick” powders are little tubes. That shape affects the burn rate and pressure curve. Powders whose grain surface area diminishes during the burn are degressive. Think fireplace log. Those whose grain surface stays about the same throughout most of the burn are neutral. A one-hole extruded powder falls into this category because as flame eats the outer surface, it consumes the grain from inside. Burning increases surface area inside as the hole gets bigger; flame outside reduces the tube’s diameter. Extruded powder grains with multiple holes – typically 7 or 19 – burn progressively. Surface area actually increases during initial stages of the burn.
In 1933 Western Cartridge Co. came up with the first successful spherical or Ball powder. While “Ball” has become a generic term, it is Western’s (and Winchester’s) own. Spherical powder manufacture differs from extruded powder production, but raw materials are essentially the same. Nitrocellulose goes through a hammer mill that grinds it to a pumice. Blended with water and pumped in slurry form into a still, the nitrocellulose combines with chalk added to counteract the nitric acids, then is dissolved by ethyl acetate, producing lacquer. Agitation and heat break the lacquer into little particles; or it’s pushed through plates much like extruded powders and chopped to bits by whirling knives. Tumbling and heating leave grains spherical. The ethyl acetate is distilled off. Then, in a water slurry, the grains pass through sizing screens. A heated still adds nitroglycerin. Burn deterrents come next, adjusting the pressure curve to spec for the powder type. A centrifuge removes excess water. The grains are tumbled in graphite, then sized again. Some spherical powders are measured blends of sizes. Purposefully crushing grains refines burn rates and pressure curves. I’m told spherical powders are easier and quicker to manufacture than extruded powders. They meter better too (albeit “short-cut” stick powders pass easily through meters and funnels).
Progressive extruded powders are intuitively the ones you’d choose for sustained thrust, the big push needed to launch heavy, small-diameter bullets from big cases against stiff bore friction. But ball powders work in this arena too, their additives throttling burn rate and gas release. Nearly all smokeless fuels have these three components: a stabilizer to prevent decomposition of the nitrocellulose (commonly diphenylamine), graphite to make handling easier and combat static electricity, and a flame retardant to reduce muzzle flash. Additives have a negligible effect on bullet velocity.
No matter what kind of powder you put in your handloads, or how much, expect only about 30% return in thrust. That’s right: typically less than a third of the energy released actually pushes your bullet. Roughly that much is lost as heat. Nearly 40% jets out the muzzle as useless exhaust! Only about .1% of the powder’s energy reaches you as felt recoil.
For more than eight centuries, gunpowder has fueled the growth of empires, and destroyed them. It has wrought carnage and imposed peace. It has fed pioneers and the builders of rails and roads erasing frontiers. It plays a central role in modern wildlife conservation. It has fattened libraries of handloaders who wisely collect and study all the data they can so the ammunition from their benches excels.
In the vats and stills birthing tiny gray tubes and spheres, and sulfurous, coal-hued granules, the fortunes of enterprising men and companies have grown – and instantly vanished. Those tales are worth the telling too. Another time.
Wayne van Zwoll has published 16 books and roughly 3,000 magazine articles on firearms and hunting. Five of his most popular books are: Shooter’s Bible Guide to Rifle Ballistics ($20), Shooter’s Bible Guide to Handloading ($20), Mastering Mule Deer ($25), Mastering the Art of Long-Range Shooting ($30) and Gun Digest Shooter’s Guide to Rifles ($20). Limited numbers are available, autographed, from Wayne at 2610 Highland Drive, Bridgeport WA 98813. Please add $4 shipping.