The weapons of war argument against the AR-15 fails on its own terms

The letters "AR" in AR-15 stand for ArmaLite, the company whose engineers designed the rifle in the 1950s. They do not stand for "assault rifle," and they do not stand for "automatic rifle." That is a small fact, and it is the first of many that get lost when the phrase "weapon of war" is used in place of an argument.

I want to do this the right way. The weapons-of-war claim is not stupid, and it is sincere. Many people hold it out of real horror at real events. So we will state it fully, identify the one thing it gets right, and then answer it in numbered points. The conclusion is that the claim fails on its own terms: if you accept its premise, that the law should treat military weapons differently from civilian ones, the law already does, and the AR-15 falls on the civilian side of that line.

The claim, stated at its strongest

Here is how its best defenders would put it.

The AR-15 was developed from a design for the American military. Its cousin, the M16, is a U.S. military rifle. The two share a profile, an operating system, a cartridge and an ergonomic layout. The civilian version fires one round per trigger pull, but a trained shooter can fire it quickly, and its detachable magazines, which hold many rounds, allow sustained fire without reloading. A rifle designed to kill efficiently on a battlefield has no business in a classroom, a concert or a shopping mall. The Supreme Court itself in Heller said M16s may be banned. If M16s can be banned, the AR-15 is the same weapon in a different dress, and a ban on the dress is constitutional.

There is real force in that. The Fourth Circuit, sitting en banc in Kolbe v. Hogan (2017), upheld Maryland's ban on AR-15-type rifles on roughly that logic, concluding that the banned rifles are so close to the M16 that they fall outside the Second Amendment. The Supreme Court declined to review the case. In the D.C. Circuit, a similar ban was upheld in the second Heller case in 2011, over a dissent by then-Judge Kavanaugh. So the argument has been accepted by serious courts.

Now the answer.

One: semi-automatic is not automatic

The claim depends on blurring a distinction, and the distinction is the whole point.

A semi-automatic firearm fires one round each time the trigger is pulled. The action uses some of the energy of the shot to eject the spent case and load the next round, but the shooter must release and pull the trigger again to fire again. An automatic firearm, a machine gun, keeps firing as long as the trigger is held and ammunition remains. The military M16 and its M4 descendant are select-fire: they have a selector that lets the soldier choose semi-automatic, burst or full-automatic fire, depending on the model. The civilian AR-15 has no such selector and does not fire automatically.

Semi-automatic rifles, shotguns and handguns are not novelties. They have been sold to the public for generations. The semi-automatic pistol that many Americans keep by the bed and the semi-automatic shotgun a duck hunter carries work on the same principle as the AR-15's action. If the "rapid fire" of a semi-automatic action is the vice, the argument condemns a large share of the guns in the country, and its defenders usually do not mean to say that.

So the phrase "weapon of war" does a sleight of hand. It describes a rifle by its resemblance to a military one, not by what it does. A rifle that looks like a soldier's but fires like a hunter's is a minivan with racing stripes: it looks fast, and it is not what the soldier carries.

Two: machine guns are already regulated, and have been since 1934

If the concern is the weapon that a military uses to put a high volume of fire downrange, the law has addressed it for ninety years. The National Firearms Act of 1934 imposed a $200 tax and a registration requirement on machine guns. In 1986, the Firearm Owners Protection Act included an amendment that barred civilians from possessing any machine gun other than those lawfully possessed before the provision took effect. The registry was frozen. Since then, a civilian who wants a true automatic weapon must buy a transferable pre-1986 gun, pay thousands of dollars, undergo an ATF background process and pay a federal tax. I trace the dates in ninety years of federal gun law in the dates that changed the rules.

In other words, the weapon of war, the weapon whose defining characteristic is automatic fire, is the one that is regulated like a controlled substance. The argument that we must keep weapons of war out of civilian hands is already the law. It was the law before most of us were born.

What the ban advocates propose is to extend the same treatment to rifles that do not fire automatically because they look like rifles that do. That is a different proposal, and it needs a different argument.

Three: Heller already drew the line, and AR-15s are on the civilian side

The claim leans on one sentence of District of Columbia v. Heller (2008), and the sentence is worth reading in full. Justice Scalia, answering an objection, wrote that if weapons "most useful in military service, M-16 rifles and the like, may be banned," then the right would seem detached from its prefatory clause about the militia. He accepted the premise, and he did not retreat from it.

But look at what the opinion says protects a weapon. The Court said the Second Amendment extends to arms "in common use at the time" for lawful purposes, and it recognized a historical tradition of prohibiting "dangerous and unusual weapons." The test asks two questions. Is the weapon in common use by law-abiding citizens for lawful purposes? Is it dangerous and unusual? A firearm that is both common and lawful is protected. A firearm that is rare and especially dangerous may be banned.

AR-15-style rifles are owned by many millions of Americans, for sport shooting, hunting, competition and home defense. Industry estimates run above twenty million, but I do not know the exact number, and anyone who quotes you one to the digit is guessing; by any plausible estimate the design is among the most commonly owned rifles in the country. That is the opposite of "unusual." A weapon owned by millions of law-abiding people for lawful purposes meets the Heller test in the most straightforward way imaginable.

The circularity objection, answered

A fair critic says: the test is circular. If a legislature bans a weapon, it will become uncommon, and then the ban will be justified by its own success. If it fails to ban a weapon until millions own it, the weapon is protected because the legislature was slow.

The objection has some bite in theory. But it fails here for a simple reason: the AR-15 became common while it was lawful and in the face of no ban, and the federal ban in 1994 did not stop that. Its popularity is a measure of how many Americans chose it. The test asks what ordinary people do with the right, not what a legislature allows after the fact.

Four: the argument from novelty proves too much

Some say the Founders could not have imagined a rifle like this. They could not have imagined the radio, the printing press that runs on electricity or the internet either, and nobody says the First Amendment is limited to hand-set type. Heller addressed this directly. It said the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the founding. The principle is the same as for speech: a right does not expire when the technology improves.

A better form of the objection is that a more lethal weapon may justify a more careful rule. That is a fair proposition, and it is why the law has long distinguished between a rifle and a machine gun. But "more lethal" has to be measured, and the measure matters. Which brings us to the evidence.

Five: what the murder tables show

The FBI's Uniform Crime Reporting program publishes a table of murders by type of weapon each year. The pattern is stable across years. Handguns account for far more murders than any other category, in the thousands each year. Rifles of every kind, the AR-15 and its relatives included, are listed in a category of a few hundred murders a year. In the tables I have seen, that figure is smaller than the number of murders committed with knives and other cutting instruments, and smaller than the number committed with hands, fists and feet. I would ask you to check the current table on the FBI's website rather than take my word for the exact counts, because the numbers change every year. The ordering has not.

I would not make too much of this, and I do not say that murders by rifle do not matter. The mass shootings that make the news, with their terrible toll, are often committed with rifles, and nothing I say should minimize the grief. They are also a small share of all gun homicide, which is mostly a handgun problem, concentrated in particular neighborhoods. A policy aimed at the rifle is aimed at the weapon the data say is used least often among the major categories. If the goal is to reduce murder, the target is badly chosen, which I take up in What the Justice Department's own studies found about the 1994 ban, where the Justice Department's own researchers found that the 1994 ban produced effects too small to measure reliably.

Six: why people choose the rifle for the home

Here is the argument ban advocates almost never engage. Why would a family pick an AR-15-pattern rifle to defend a house?

Consider the features that the critics call military. The rifle is light, and its recoil, because of the cartridge it fires, is mild compared with many hunting rifles and shotguns. The stock adjusts in length, so a smaller person, or a person of any size, can fit the rifle to their body. The sights and the weight are friendly to a beginner. The magazine holds more rounds than a revolver, and a person who is frightened, in the dark, under stress, and perhaps facing more than one intruder, will miss more often than a range shooter does. These are arguments from the practical needs of ordinary people, not from battlefield doctrine. I discuss why this matters most to a smaller or weaker person in the equalizer, why a firearm matters most to the smallest person in the room.

You may disagree about whether the rifle is the best home-defense choice. Many experienced people prefer a shotgun or a handgun, and no one is required to own a rifle. But Heller's test treats common choice for lawful purposes, self-defense included, as the mark of a protected arm. On that test the choice belongs to the citizen, not the committee.

Seven: the constitutional question

The Second Amendment was written to protect the people's right to keep and bear arms as a check on a government that might become dangerous. Madison wrote in Federalist 46 about the advantage Americans have over the people of other countries, "being armed," in a passage that makes sense only if the arms in question are of a kind that a citizen militia could use, which is why Madison's Federalist 46 and the advantage of being armed that tyrants fear is worth reading. A right that protects only the arms no army would use, ducks guns and antiques, would be a right to be no threat to anyone. That is not what the text says. The Militia Act of 1792 required able-bodied men to own a musket, the military arm of the day, and I discuss it in Every able-bodied man must own a musket, the Militia Act of 1792 and its heirs. The founders thought a citizen should own the same kind of weapon the soldier did, which is the opposite of the weapons-of-war premise.

I want to be fair on the point: Heller's language about M16s limits this. The majority accepted that some military-style arms can be regulated. But the controlling distinction, the one the Court wrote, is not military look. It is common use for lawful purposes, and automatic fire is the clearest case the law has already drawn.

What a reasonable person can say

I think a reasonable person can hold that the free-fire capacity of a magazine is a legitimate subject of debate, and I say so with the understanding that the debate belongs in a legislature and in the courts, in the open. I do not think a reasonable person can hold that the AR-15 is a machine gun, or that the law has ignored the distinction between military and civilian arms for ninety years. And a person who wants a ban has to answer, with evidence, the question I put in the post on the 1994 law: what, exactly, did it do?

There is also a question of vocabulary and fairness in how this story is told. Coverage routinely says "military-style" and "weapon of war," terms that describe the look and not the function, to a public that does not know the difference between a semi-automatic and a select-fire rifle. The words do the arguing. I look at that habit in assault weapon, ghost gun, arsenal, how news vocabulary does the arguing, and it is fair to say a reader who understood the mechanism would find the label less persuasive.

The case in brief

1. The AR-15 is a semi-automatic rifle, firing one round per trigger pull, and it is not the select-fire M16 the military issues.
2. Machine guns have been regulated since the National Firearms Act of 1934 and effectively frozen for civilians since 1986, so the weapons-of-war concern is already addressed by law.
3. Heller protects arms in common use for lawful purposes, and the AR-15 is among the most commonly owned rifles in the country; the "dangerous and unusual" exception does not fit it.
4. The FBI's murder-by-weapon tables list rifles of all types in a small share of murders, behind handguns and, in the tables I have seen, behind knives and hands and feet, and many people choose the rifle for home defense for practical reasons.
5. The founders expected citizens to own the arms of the militia, so the premise that civilians should have only non-military arms runs against the text's history.

What you can do: open the FBI's most recent table of murder by weapon type and read it yourself, then ask your state legislators what problem a proposed rifle ban is meant to solve and what evidence shows it would.