Category: All About Guns
The AR-15 rifle is the most popular long gun in America. It is built around upper and lower receivers cut from aircraft-grade aluminum.
Aluminum is a ubiquitous material in modern society. Back in 1956 when Gene Stoner and a few others designed that first AR-15 rifle around aluminum receivers, they literally changed the landscape. In the 1980s, everybody in the combat handgun world was churning out high-capacity, aluminum-framed pistols. Nowadays, we discard or recycle aluminum beverage cans by the zillions.
One of the neat things about aluminum is the way it sort of heals itself. Pure aluminum is highly reactive when exposed to air. However, the resulting aluminum oxide is exceptionally stable. This results in a natural microscopic protective coating on exposed surfaces. In applications like window frames, mechanical trauma from repetitive use results in tiny scratches that instantly oxidize, ensuring a robust material that resists environmental degradation.
Aluminum is relatively soft and easy to both extrude and machine. There are dozens of recognized aluminum alloys. Most AR parts are formed from 6061, which includes trace amounts of silicon, magnesium, copper and chromium. The 7075 alloy includes zinc in place of the silicon.
The 1980s was the decade of the “Wonder Nines.” These high-capacity 9mm pistols were built around aluminum frames.
Digging Deeper
Aluminum is indeed fascinating stuff. It has an atomic number of 13 and is roughly one-third of the density of steel. Aluminum is the 12th most common element in the universe and the third-most common element in the Earth’s crust right behind silicon and oxygen. It accounts for 1.59% of the Earth’s mass. The stuff is everywhere.
Despite the fact that aluminum was so common in nature, back in the late 1800s it was actually considered a precious metal. Gram for gram, aluminum once cost more than both gold and silver. Napoleon III reserved his aluminum flatware to impress visiting dignitaries. Lesser visitors got the silver.
In 1884, the Washington Monument was capped with a six-pound piece of aluminum. The total national output of aluminum that same year in the United States was only 112 pounds. Aluminum was revered similarly to platinum. How was it that such an abundant material might have been considered so rare and valuable a short century or so ago? That all depends on how you refine it.
While there are scads of elemental aluminum in the earth’s crust, prior to the late 1800s, it was terribly difficult to access. Most elemental aluminum is found in the form of a natural ore called bauxite. By 19th-century standards, extracting usable aluminum from this ore was nigh impossible.
Nowadays, lots of guns are built out of aluminum. This custom
takedown AR short-barreled rifle and this FN SCAR-15P carbine
are counted among them.
Find a Need and Fill It
In 1886, a 17-year-old college student named Charles Hall was sitting in a chemistry class when his professor told him about the aluminum quandary. Hall’s professor actually said that if someone could devise a cost-effective method for extracting aluminum from bauxite, he would become the richest man in the world. Intrigued, the teenager went home determined to find a better way.
For the next five years, Charles Hall toiled in a workshop he had erected inside his family’s woodshed. Eventually, his perseverance paid off and he discovered a unique process that would produce aluminum from bauxite using electricity. At age 22, Charles Hall was indeed about to change the world.
Bizarrely, at exactly the same time in France, another 22-year-old, this one named Paul Heroult, discovered the identical technique. The resulting electrolytic extraction of aluminum from bauxite has become known as the Hall-Heroult Process.
AR-15 receivers are lightweight, ubiquitous and strong.
Changing the World
Because both men discovered the process at the same time, neither established a monopoly. However, there was more than enough sweetness to go around. The young Charles Hall founded Alcoa, short for Aluminum Company of America. In 2023, Alcoa’s total revenue was $10.55 billion.
Extracting usable aluminum is still a terribly energy-dependent undertaking. As a result, most aluminum smelters are located in places where electric power is cheap. Production of one kilo of aluminum requires the equivalent of seven kilos of oil energy. That compares to 1.5 kilos for steel and 2 kilos for plastic. Today, 5% of the electric power produced in the United States goes toward smelting aluminum.
Ruminations
I am pretty quick to denigrate young people. With the exception of my own kids, I just don’t find the youth of today terribly impressive. In fact, I’m not sure I’d trust your typical Information Age 17-year-old unsupervised with electrical tape, much less a homebuilt metal smelting workshop. However, when Charles Hall was seventeen, he took up the challenge to find a better way to extract aluminum from rocks. In so doing, he did become lyrically wealthy.
Had Charles Hall been born a century later, he would not have been able to buy a beer or own a gun when he first embarked upon his holy quest to conjure aluminum from the ground. However, through hard work, perseverance and no small amount of talent, this driven young man did, indeed, change the world. So, the next time you drag your favorite AR-15 out to the range, just appreciate that some teenager figured out how to extract the stuff they used to make it.
Categories
Remington-Keene POV firing
The city of Denver has infringed upon the rights of its citizens for decades by banning the ownership of common, constitutionally protected semi-automatic rifles. Now, the U.S. Department of Justice (DOJ) is taking the city to task over the infringement.
Passed back in 1989, the ordinance makes it illegal to carry, store, keep, manufacture, sell, or otherwise possess what it calls “assault weapons” in the city. On May 5, the DOJ filed a lawsuit in the U.S. District Court for the District of Colorado seeking to have the ban ruled unconstitutional and stricken from the books.
“The Constitution is not a suggestion and the Second Amendment is not a second-class right,” Acting Attorney General Todd Blanche said in a news release announcing the action. “Denver’s ban on commonly owned semi-automatic rifles directly violates the right to bear arms. This Department of Justice will vigorously defend the liberties of law-abiding citizens nationwide.”
In 2008, the U.S. Supreme Court, in its landmark decision District of Columbia v. Heller, held that the Second Amendment protects the right of law-abiding citizens to possess weapons that are in common use for lawful purposes. In the complaint, the DOJ argues that Denver’s law directly violates that critical aspect of the ruling.
“In reality, the firearms the City calls ‘assault weapons’ include ordinary semi-automatic rifles possessed by millions of law-abiding Americans,” the complaint explains. “Indeed, Americans own literally tens of millions of AR-15 style rifles, the paradigmatic ‘assault weapon’ covered by the Ordinance. As the Supreme Court has recently recognized, the AR-15 is the most popular rifle in America.
When the City banned AR-15 style rifles with standard capacity magazines, it banned an arm in common use for lawful purposes by law-abiding citizens. Therefore, the Ordinance violates the Second Amendment, and the United States brings this action to vindicate the rights of Denver citizens whose rights have been—and are continuing to be—violated by Defendants.”
Assistant Attorney General Harmeet K. Dhillon, head of the DOJ’s Civil Rights Division, said her office stands ready to fight this ordinance and any unconstitutional gun laws throughout the nation.
“I have directed the Civil Rights Division, through our new Second Amendment Section, to defend law-abiding Americans from restrictions such as those we are challenging in these cases,” Dhillon said.
“Law-abiding Americans, regardless of what city or state they reside in, should not have to live under threat of criminal sanction just for exercising their Second Amendment right to possess arms which are owned by tens of millions of their fellow citizens.”
Ultimately, the DOJ is asking the court to declare the law unconstitutional under the Second Amendment, enjoin defendants and their agents from enforcing the ordinance to the extent it bans the possession of AR-15-style rifles with standard-capacity magazines, and “such other and additional relief as the interests of justice may require.”