Over millions of years, mankind devised methods of ensnaring animals as a means of survival. For instance, launching various projectiles, such as stones, spears, and knives, led to catching larger prey, which could feed entire villages for months. As civilization progressed, mankind was able to develop faster and deadlier weapons that could not only provide food for the survival of families, but also protect against intruders. The invention of gunpowder propelled war and conquest as it led to the development of firearms. Gunpowder can be traced back to ancient China over one thousand years ago, where it was primarily used in firecrackers and sparingly for military use. As trade and barter between nations increased, the dissemination of knowledge behind gunpowder emerged across Europe; however, it was not implemented into battle until military leaders confirmed the effectiveness of impelling projectiles via gunpowder. In fact, the brute force of the projectiles penetrating the knight-soldiers armor and fortresses garnered the respect across several kingdoms.
The composition of gunpowder consists of sulfur, charcoal, and saltpeter, also known as potassium nitrate. Gunpowder earned its explosive reputation due to the blunt force of one mole producing six moles when the mixture becomes ignited. After experimenting with the explosive nature of gunpowder, military combat began launching projectiles by enclosing blunt objects within an enclosed space of a metal tube and then ignited the compound. While modern gunpowder has barely changed from its primitive origin, successful attempts have refined it into a chemical composition that only requires a small quantity and residue to produce the greatest expansion. Technological advancements have developed identification techniques that allow for closer examination of each of the specific components contained within the gunpowder itself. This enables forensic scientists to investigate and identify the bullets and weapons used during crimes.
The introduction of firearms primarily focused on military development and still continues to improve even to the present day and age. Soldiers depend on firearms to survive during combat. A firearm must be reliable, accurate, forceful and fast in order to bring down a target. Most importantly, the firearm's reliability factor led to distinct developments that would revolutionize war and conquest. One of the most primitive weapons used in combat included a matchlock design that employed a burning wick on a spring that cocked back and released into a small metal pan while pulling the trigger. The gunpowder contained in the metal pan ignited, which sent a flame through a small hole and into the barrel of the weapon. This set off a series of gunpowder ignitions and charges in the barrel chamber that eventually propelled a projectile forward. Bullets are the modern form of projectiles used in today's firearms.
Improvements to the archaic matchlock design included a contraption known as the wheel-lock, a spinning metal plate that ignited sparks into the metal pan holding a primer powder. Additionally, a flint-lock, or a mechanism used to hold a flint in place until was released by a trigger, was used to strike a steel plate to ignite sparks into the metal pan. Some tweaks evolved into a process known as the percussion ignition, which consisted of an interlocked hammer that struck a cap that contained a volatile substance that exploded on impact. This chemical reaction sent a flame into the barrel chamber, which then propelled the projectile to its target. Radical changes altered the system by including small bullets, a gunpowder charge, and primer into one single cartridge, which was introduced directly into the gun chamber. Muzzle loaders were used to stuff the bullet and powder at the top of the barrel before the cartridge was developed for precise shooting. Muzzle loader weapons contained a smooth bore with a round led ball. While these weapons were deadlier than other primitive variations, the limited range and accuracy became a problem for military's that fell behind in their strategic pursuits.
Minor length adjustments to the smooth bore eventually evolved to produce improved accuracy; however, the longer-ended bores introduced mobility problems for combat soldiers. Eighteenth century gunsmiths discovered that adding spiral grooves to the smooth bore that would cause the bullet to spin and ultimately improve overall accuracy. These spiral grooves had been reduced to curtail the foul smell produced by unburned gunpowder residue. This adjustment led to the concept of rifling in modern firearm barrels. Rifling improved the overall accuracy markedly, because of the twisted effect between the metal lands and spiral grooves inside the gun barrel. In fact, the bullet grips the rifling that spins the bullet as it projects out of the gun barrel. Rifling produces more stability and less tumbling while the bullet travels to it target, which creates a consistent and longer flight path. Each modern weapon imparts different patterns and formations as the bullet launches from the gun barrel. These distinct patterns aids forensic scientists to identify the weapon and bullet used during a crime.
The breech-loading firearm developments led to improvements of speedier loading. The introduction of multiple chambers, such as the revolver, enabled the gunman to muster multiple shots to its intended target. Other mechanisms included sliding and pumping attachments that loaded additional cartridges into the chamber after the original shots expire. Nineteenth century inventors, such as Henry Maxim and Richard Gatling, created schemes to rapidly fire a large quantity of rounds without ceasing, a weapon that would be termed the “machine gun.” Machine guns were redesigned and refined during the World War I and II. Modern assault weapons used by military combat teams around the world employ a mechanism that expands gases and emits the gunpowder by force resulting in an estimated six hundred rounds per minute.
The force of a traveling projectile can be calculated by the following formula:
Kinetic Energy (KE) equals ½ Mass * Velocity squared
Early gunsmiths realized that the key to enhancing the kinetic energy was to increase the weapon's caliber. The weapon's caliber refers to the overall diameter of the smooth bore of the gun barrel, often resultant in decimal fractions of an inch or metric millimeters. A handgun or rifle was referred to as .38 and .45 cal or 9mm. Modern weapons also increase kinetic energy through a concept known as velocity, or the increased force caused by the ignition of gun powder projecting the bullet through the chamber and barrel.
Improvements to the overall bullet velocities increased with full-metal jackets created out of copper or copper alloys. Full-metal jackets allow bullets to travel down the gun barrel more easily than exposed lead. Full-metal jackets are less likely to fragment upon impact and may travel to hit a target while using less kinetic energy. Therefore, full-metal jackets cause less tissue damage than non-jacketed ammunition. Full-metal jackets are used in numerous countries across the globe, which adheres to the Hague Convention held in 1899.
The History of Firearms Identification (PDF): An extensive abstract paper detailing the evolution of firearms, including the identification process employed by forensic scientists in order to discover the weapon used during a crime.
Chinese Contributions to Technology: A comprehensive article addressing the contributions of the ancient Chinese to modern technology, including the discovery and implementation of gunpowder in military pursuits.
Gunpowder: An academic historical account of gunpowder, including its original intent, developments, and evolution into the deadliest forms of modern warfare.
Muzzle Loaders: A description of the muzzle loader, an early musket used by combat soldiers that involved loaded the gunpowder and bullet at the top of the gun barrel before pulling the trigger.
Making a Matchlock Musket: A comprehensive how-to tutorial that explains detailed steps to creating a matchlock musket from scratch. Matchlock muskets were used during the Queen Elizabethan period and the English Civil War.
The American Revolution: The Ferguson Rifle: The Ferguson rifle was a breech-loading flint-lock used during the American Revolution around the year 1780. It was designed by a soldier and inventor named Patrick Ferguson.
The Rifle versus The Musket: A web page describing the significant differences and enhancements between the musket and the rifle. It outlines the convenience of the rifling mechanism as opposed to the muzzle loaders.
The American Firearms Institute: Important Dates in Gun History: A time-line of important dates involving firearms beginning from 142 A.D. to 1983.
Gun Information for Shooters: Matchlock: A first-person encounter of an archaic matchlock design musket, which also includes a real-time video of it in operation.