You are the owner of this article.
editor's pick alert top story
Firearm Laws

After 25 years, defining an assault weapons ban hasn't gotten easier

  • 8 min to read
After 25 years, defining an assault weapons ban hasn't gotten easier
Gun Control Conservative Courts

A custom-made semi-automatic hunting rifle with a high-capacity detachable magazine is displayed at a gun store in Rocklin, Calif. California has some of the toughest gun laws in the nation, including a ban on the type of high-capacity ammunition magazines used in the nation’s three most recent public shootings, which claimed nearly three dozen lives. How long those types of laws will stand is a growing concern among gun control advocates in California and elsewhere. 

Another rash of mass shootings, this time two in a single weekend, has renewed the national debate on gun reform. It also renewed a concept that is controversial in it’s very definition — an assault weapons ban.

U.S. Sen. Bob Casey used the term during a rally in Harrisburg last week, part of a list of gun control measures he hopes the Senate will take up. When other speakers mentioned a possible ban during the rally in front of the assembled group of gun reform advocates, the term received the loudest applause, even more so than calls for universal background checks and red flag laws.

Gov. Tom Wolf, although he has voiced support for an assault weapons ban in previous statements, did not name it as one of his three priorities last week. He instead pressed state and federal legislators for universal background checks and for the state to pass it’s red flag law, known as Extreme Risk Protection Orders.

The latter has some Republican backing, and appears to be the strongest measure that Wolf might actually get out of the state’s GOP-controlled Legislature.

But even if it is last in a long line of possible gun reforms, the mere mention of an assault weapons ban tends to bring out conflicts of fact that make discussions more difficult.

U.S. Sen. Pat Toomey was embroiled in this last week when Democrats roundly criticized him for declining to endorse an assault weapons ban because they’re “an extremely popular firearm” during a Fox News appearance.

Sen. Pat Toomey


“Guns that are described as assault weapons are almost invariably no more powerful than ordinary hunting rifles,” Toomey said during the interview.

“They look different, they’re painted black and they’ve got features that an ordinary hunting rifle doesn’t have, but they’re no more lethal.”

Assault weapons are popular — one in every five guns sold in the United States is a rifle based on the AR-15 platform, by far the most popular gun associated with the term “assault weapon,” according to the National Shooting Sports Foundation.

Toomey is also technically correct in that rifles commonly considered assault weapons are less powerful — in terms of energy output of the bullet, measured in joules or foot-pounds — than traditional hunting weapons.

But recent studies, and the historical record, indicate that the reduced energy output and corresponding ease of rapid fire is actually what makes such weapons more deadly in mass shooting situations, complicating Toomey’s claim that “they’re no more lethal.”

It’s also what makes assault weapons ban proposals difficult to evaluate. The 1994-2004 federal assault weapons ban, which many proposals today are still based off of, attempted to define the guns in a way that left a large number of loopholes.

Christopher Koper

Christopher Koper


That is the conclusion of the most widely cited study of the ban, a report done for the U.S. Department of Justice by criminologist Christopher Koper, a professor at George Mason University.

Koper quantified what many — both supporters and critics of gun control — had pointed out, that the law’s attempt to define assault weapons by specific models and/or specific features, such as folding stocks, flash hiders, bayonet mounts, and others, was problematic, leaving many semi-automatic rifles outside the scope of the ban.

Further, although the ban stopped the manufacture of magazines larger than a 10-round capacity, it didn’t prevent the manufacture or selling of guns that could accept high-capacity magazines already in circulation.

For instance, certain models of firearm and “copies or duplicates thereof” were banned, including the AR-15 and AK-47. But the Bureau of Alcohol, Tobacco and Firearms allowed guns to be sold that were based on banned weapons systems but had been modified enough to pass the “copies or duplicates” test.

Heavy-barreled AR-15s, ostensibly for target shooting, were still sold and could accept high-capacity military magazines. A number of foreign “sporting” rifles were permitted to be imported even though they were based on the Kalashnikov action, albeit without flash hiders and with “thumbhole” stocks that evaded the ban on pistol-grip weapons.

Cassandra Crifasi

Cassandra Crifasi

“Generally speaking, the biggest issue with the federal assault weapons ban is it’s too easy for gun manufacturers to leave one feature off of a gun so that it didn’t qualify,” said Cassandra Crifasi with the Center for Gun Policy and Research at Johns Hopkins.

Koper, and other researchers since, uncovered a few fundamental issues. The number of crimes in which assault weapons are used is small, about 8 percent at most, with the vast majority of gun crimes involving handguns.

However, during the 1994-2004 ban period, the use of assault weapons in crimes did decline, anywhere from 17 to 72 percent, depending on the study area, Koper found.

But this decline in the use of weapons covered under the ban was “offset throughout at least the late 1990s by steady or rising use of other guns equipped with large-capacity magazines.”

Mass Shootings High Capacity Magazines

Sen. Richard Blumenthal, D-Conn., speaks at a news conference on an proposed amendment to ban high capacity magazines in guns, on Capitol Hill in Washington. In the time it takes for a driver to wait through a red light, a shooter with a high-capacity magazine can kill and injure dozens of people before police can stop the carnage. It only took 30 seconds for the man who opened fire in a downtown section of Dayton, Ohio, over the weekend to kill nine and injure dozens, thanks to the 100-bullet drum attached to his rifle.

Mass shootings

Even though they represent a small portion of gun crimes overall, assault weapons are used more often in mass shootings and shootings in public places, and are more deadly when they are used.

A study published earlier this year in the Journal of Trauma and Acute Care Surgery found that assault rifles accounted for roughly 86 percent of all mass shooting fatalities from 1981 to 2017, and that fatalities were 70 percent less likely during the 1994-2004 ban era.

“There is some evidence to suggest that when mass shootings did occur during the time of the assault weapons ban, that there were fewer casualties in those events, and since that has lapsed the casualty counts have been increasing,” Crifasi said. “But the biggest issue with an assault weapons ban is if manufacturers can make minor modifications and produce guns that don’t fall under the prohibition.”

A study published last year in the Journal of the American Medical Association compared a series of similar “active shooter” incidents, as defined by the FBI, and found that those involving semi-automatic rifles resulted in an average of 4.25 persons killed and 5.48 wounded, versus 2.49 killed and 3.02 wounded in incidents that did not feature a semi-automatic rifle.

All of these issues — Toomey’s assertion about the “power” of assault weapons, the difficulty in writing legislation to define them, and the enhanced lethality of semi-automatic rifles colloquially referred to as assault weapons — gets to the issue of what makes an assault weapon what it is.

The military definition is relatively restrictive. An “assault rifle,” for soldiers, must be capable of select-fire, meaning the shooter can toggle between semi-automatic mode, in which the trigger must be pulled separately for each round fired, and full-auto, in which the rifle continues to cycle for a long as the trigger is depressed.

Few firearms capable of full-auto fire are available in the United States, following legislation in 1986 that prohibited the further production of such weapons and restricted the possession of existing fully automatic firearms.

They worry that federal courts, especially if Trump wins a second term next year and Republicans hold the Senate, will take such an expansive view of Second Amendment rights that they might overturn strict gun control laws enacted in Democratic-leaning states.

Most firearms colloquially referred to as “assault rifles” in the civilian world are semi-auto-only; the Associated Press recommends using the term “assault weapon” to describe such civilian versions of military rifles in order to avoid confusion with true military select-fire weapons.

But in a practical sense, the select-fire distinction is not critical. The U.S. Army’s marksmanship field manual for AR-15 rifles states “the most important firing technique during modern, fast moving combat is rapid semiautomatic fire.”

“Rapid-fire techniques are the key to hitting the short exposure, multiple, or moving targets described previously. If properly applied, rapid semi-automatic fire delivers a large volume of effective fire into a target area. The soldier intentionally fires a quick series of shots into the target area to assure a high probability of a hit,” according to the basic training document.

Long history

Historically, the key feature of the AR-15 for the U.S. military was what is called the “intermediate cartridge” or “high velocity small caliber principle.”

When the U.S. Army began development of the rifle in 1957, it defined two key features — a loaded weight of six pounds or less, and the use of a .22-caliber cartridge (meaning the bullet is approximately .22 inches in diameter) that has enough powder capacity to drive the bullet to faster speeds than previous military rounds.

This is a smaller, lighter bullet than the heavyweight .30-caliber rounds that had been used during the world wars and emphasized long-range performance. But the Army believed that pushing a smaller projectile to a higher velocity would give the new rifle wound ballistics that were just as deadly within most practical combat ranges, while also limiting recoil, allowing even untrained soldiers to make rapid follow-up shots.

Experience in Vietnam, where the AR-15 was finally adopted by the military as the M-16 rifle, proved that the new cartridge was a success. The heavy recoil of the M-16’s .30-caliber predecessor, the M-14, meant that rapid fire was extremely difficult. By contrast, even soldiers with minimal training or experience could rapidly place shots with the AR-15 at the Army’s specified maximum range of 500 yards, facilitated by the flatter trajectory of the smaller, faster bullet.

In 1962, the Department of Defense found that “in overall squad kill potential the AR-15 rifle is up to five times as effective as the M-14 rifle,” and that “it is significantly easier to train the soldier with the AR-15 than with the M-14 rifle.” The rifle was adopted because, somewhat counter-intuitively, it’s lower power made it a more efficient killer than the M-14.

Semi-automatic-only versions of the M-14 have all the same features as the M-16 that would qualify both as assault weapons under the 1994 ban definition — detachable magazines, flash hiders and bayonet lugs. But only the latter fires the lightweight 5.56x45 mm cartridge, which is more conducive to rapid fire, and would historically be considered an assault rifle if equipped for select-fire.

In the years following World War II, those studying the first assault rifle, the German Sturmgewehr, considered the scaled-down cartridge, along with high-capacity detachable magazines to further facilitate rapid fire, as the defining feature of all subsequent assault weapons, particularly the AR-15.

“After the war [the Sturmgewehr] was examined and dissected by almost every major gun-making nation and led, in one way and another, to the present-day 5.56 mm assault rifles,” according to Jane’s Defense.


This has led some nations to institute gun control based on the use of intermediate cartridges of military origin. In France, a special license is required to own “Class B” firearms, which include any gun chambered for the 5.56x45 mm cartridge, as well as the 5.45x39 mm and 7.62x39 mm Kalashnikov rounds.

Rifles that are ostensibly more powerful in terms of energy output, but are less conducive to rapid fire, are in a less restrictive class per their public danger (fonction de leur dangerosité), and can be much more easily acquired, according to France’s public administration website.

But in the United States, current proposals to control assault weapons still rely fundamentally on the same definitions established in 1994. Sen. Dianne Feinstein’s updated 2013 ban proposal, which has been introduced in many state legislatures as well, adds dozens of new models of firearm to the list, and limits guns to having only one of the Clinton-era assault weapons features.

But given how fast the industry moves, many experts doubt that the 1994 model is still viable.

At least two pieces of assault weapons ban legislation have been filed in the Pennsylvania Legislature. But both fail to list a number of popular assault weapons that would be perfectly legal to sell with a simple change of stock and muzzle device.

For instance, semi-automatic rifles based on the Israeli Tavor action, now widely available in the U.S., are not listed. Nor are any of the assault weapons that are based on the AR-15 but use a piston-operated upper receiver, as opposed to the original direct gas action. One of these, the SIG MCX, was the weapon of choice in the 2016 Orlando nightclub shooting.

Rather than trying to parse a definition of assault weapons and then ban them, Crifasi suggested increased improved oversight on all semi-automatic rifles.

“Rather than banning assault weapons, we can just have higher standards,” Crifasi said. “Washington state raised the minimum age for anyone purchasing a semi-automatic rifle, and they also introduced some mandatory safety training that passed as part of a ballot initiative.”

Such measures are too new to have empirical backing, but “logically, given what we know about the failures of the federal assault weapons ban, this may be an alternative way to address the issue,” Crifasi said.

Get Government & Politics updates in your inbox!

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Email Zack at


Get up-to-the-minute news sent straight to your device.


News Alerts

Breaking News