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Roger Weller, geology instructor
by Douglas Powers
Gun Powder: The Explosive History
If you’ve ever fired a gun, the agent that propels the bullet is a type
of gun powder. Ever lit off a firework? Yup, the propellant in that was also gun
powder. Fan of pyrotechnics in movies or concerts? Gun powder as well (Michael
Bay owes his career to gun powder.) From its rudimentary, basic uses at its
creation, to the modern, complex uses; gun powder has played a pivotal role in
shaping the world that it is today.
The Creation of the “Magic Powder.”
Though it is clear that it was invented by the Chinese; exactly when gun powder was discover remain a toss-up to this day. The general consensus among researchers believe it may have been created at some point during the Tang Dynasty (9th century China,) however other writings, such as Wujing Zongyao, date it closer to the Song Dynasty (11th century China;) however the latter date’s writings may have been re-written text from the former. Regardless of what period it was discovered, it was discover by Chinese alchemists, searching for an “elixir” for immortality (which is ironic considering one of its primary uses, is for waging war.) As the year progressed, so did the uses for gunpowder, leading to the creation of several popular inventions such as grenades, rockets, fireworks and even an early flame thrower!
Though the composition of gun powder has gone through several changes to better fit its demands, it was originally composed of three items: Sulfur (S), serving as the fuel source, saltpeter (potassium nitrate KNO3,) serving as the oxygen supplier and Charcoal (C7H4O), serving as the Carbon (C) source for additional fuel.
Charcoal was a reasonably abundant and easily accessible material, potassium
nitrate was mostly gathered by collecting the large quantities of bat guano,
soaking it in water for 24 hours, and then collect the crystals that had
filtered from the water. Though it was abundant in China, during the 3rd
century, the Chinese made the discovery that sulfur could be extracted from a
mineral known as pyrite (This discovery was greatly accepted in areas that
didn’t have a normal abundance of sulfur.)
Early text from the Wujing Zongyao, 1044, listing gun powder’s ingredients.
Here is the chemical equation for gun powder, in it’s simple form:
2 KNO3 + S + 3 C → K2S + N2 + 3 CO2.
This is the same simplified formula, only balanced:
10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4
+ 6 CO2 + 5 N2.
What determines how explosive the powder rests on the percentage of saltpeter in the mixture. The earliest form of gun powder contained 50% or less saltpeter, and resulted in a highly flammable powder vs an explosive one. Around the mid-14th century, the gun powder formula had achieved its full potential, with a nitrate ratio of 12% to 90% over a span of six different formula. This was the formula that would serve as a base for many variations of powder as time progressed.
The original formula, gun powder; nick named “Black Powder,” due to its color.
Other types of gun powder:
As gun powder grew in popularity, other nations began changing the formula to either make it more stable, or effective; here are some of the variations of gun powder:
To maximize the explosive potential, the mixture was needed to be compressed so the particles inside the mixture could be reduced to individual, dense grains. Due to safety reasons, this process requires the powder to be damp, so there is no possibility of it going off. The mixture was then pressed in molds for varying degrees of time. This allowed for the particles to be as dense as possible, maximizing its effectiveness. This was discovered to make the projectile that the powder propel around 30 feet per second faster than previously.
A corning “puck;” used to mold the powder during the corning process.
Invented in the United Kingdom, 1889 by Sir James Dewar, Sir Frederick Abel, and Dr. W. Kellner, after the U.K. government requested a replacement for gun powder; one that wouldn’t cause and overabundance of smoke. It contains a mixture of 58% nitroglycerine, 37% nitrocellulose and 5% petroleum jelly; in addition, acetone was added to produce the solidify the mixture together (it was commonly shaped together into blocks and cords.) This type of propellant was used throughout World War One, and World War Two, eventually evolving into Improved Military Rifle (IMR) powder, currently in use today by most militaries.
Cordite “rods,” that are packed into the casing of the round; serving as a propellant.
Developed in Germany around 1884 composed of 79% nitre, 3% sulfur, and 18% charcoal; it was given its name after the brown color to it, due to it being made from rye straw that wasn’t completely burned. This particular powder had a slower burning rate as a result. (not to be confused with “brown-brown” powder, which is a type of drug.)
Developed in 1911 and sold by Winchester, it was a type of smokeless powder that was far less corrosive than other smokeless powders, and did not require the shooter to clean the rifle bore after every shot, (unlike other powders at the time.)
Images courtesy of Google Images.