As an AR 15 owner, you hold some impressively engineered machinery in your hands. Everything from the gas tube to the ejection port and even accessories like a KeyMod handstop have been carefully designed down to the smallest detail to provide better accuracy, less weight, and even handle smaller caliber rounds with just as much impact. Now, think about your AR 15, perfectly accessorized and modified, in comparison to a musket with a bayonet - the sort of firearm used during the Revolutionary War. Firearms have come a long way since they were first developed!
The specifics of early firearm development is hard information to track, but historians have narrowed the earliest firearm-style weaponry to China as far back as the 1200s. That’s at least 800 years of engineering, technology development, and lessons learned!
The firearm in any iteration began as what historians call the fire-lance. According to Kenneth Chase, author of Firearms: A Global History to 1700, the fire lance was what amounted to a spear with a gunpowder-powered projectile at the end - imagine part spear, part hand cannon, and part early flamethrower. It was not very accurate and required a close range to have any effect, but it paved the way for more minds to modify into more useful and impactful weaponry.
The shrapnel expelled by a fire-lance showed a lot of promise, but it was hardly accurate. Those initial advances toward a true firearm started with a barrel full of projectiles strapped to the end of a fire-lance. In order to improve accuracy, the Chinese started creating projectiles that fit closer to the size of the barrel - a historical approximation of current barrel size and ammunition caliber. From there, the bamboo barrels were replaced with metal for durability and were elongated to create a more effective propellant effect. In essence, it was the primary components of a firearm at the end of a long stick or spear.
Around this same point in history, groups of Arabs in the Middle East developed gunpowder-powered weapon in the realm of a hand cannon. Historians are unsure whether this group developed gunpowder independently or if it was introduced by invading Mongols.
Historians aren’t entirely sure when or how those early firearms made it from Asia across the expansive landmass to Europe. It could possibly be trade and travel along the Silk Road that slowly trickled gunpowder and fire-lances across that great distance, or it may have been Mongol invasions as they pushed across the Middle East and into Eastern Europe in the early 1300s.
By the mid-1300s, there are historical mentions of firearms in England, Italy, and Russia. From there, designs for guns were developed and refined based on soldiers’ usage. Barrels became longer and flint striking mechanisms were developed to make it easier to fire projectiles.
At this point in history, firearms have become more recognizable as guns rather than explosive barrels on the ends of spears. Better materials and improving technology are a large part of the fuel behind the continued westward expansion that saw England, Spain, Italy, France, and other European powers taking control of a vast majority of the New World.
Through the 1500s and on up to even the 1800s, ammunition was not standardized - in fact, ammo was primarily whatever was handy: rocks, nails, bits of metal. If it fit in the barrel, solid, and was at hand, it was probably used. In the 1850s, the Springfield Armory created the first breech-loaded rifle, which encouraged more standardized ammunition.
Most of the technological advancements that make firearms recognizable today came around the time of the Civil War. Shortly before, revolvers began being produced, followed soon after by repeating revolvers. Then came the Gatling gun, which was the first successful multi-fire firearm, and the Maxim, the first self-loading firearm.
By and large, many of the advancements in firearms in the 19th and 20th centuries came about because of soldiers’ needs during war, primarily World Wars I and II. Staying true to form, the AR 15 was initially developed by ArmaLite as a replacement for a handful of different gun models used by US soldiers during World War II and the Korean War.