The Ten-Round Fiction.

Fourteen states and the District of Columbia currently cap magazine capacity, most of them at ten rounds. Massachusetts has lived under its limit since 1994. California’s sale ban dates to 2000. New York and Connecticut joined in 2013, New Jersey tightened to ten in 2018. That’s three decades of real-world data, across tens of millions of people, on one simple question: did any of it work?

The honest answer — backed by the government’s own researchers, the states’ own compliance data, and the Commonwealth’s own court records — is: not much. Except a growing pile of paperwork felonies hanging over the heads of the people who were never the problem in the first place. Every statistic in this article links to a primary source. Click them. Read them. This is the data the people writing these laws hope you never look up.

The Government Studied Its Own Ban. Read What It Found.

When the 1994 federal Assault Weapons Ban — the original nationwide 10-round magazine limit — came up for renewal in 2004, the Department of Justice funded criminologist Christopher Koper to assess a full decade of it. His official report concluded: “Because the ban has not yet reduced the use of LCMs in crime, we cannot clearly credit the ban with any of the nation’s recent drop in gun violence.” The same report noted that in a study of handgun attacks in one city, only 3% of gunfire incidents involved more than 10 shots fired. Ten years of a nationwide ban, and the government’s own reviewers could not find a measurable effect.

Nine years later, when Washington was debating a new ban after Sandy Hook, the National Institute of Justice’s deputy director, Greg Ridgeway, wrote an internal memo that was never meant for the public. On magazine restrictions, it said the 1994 ban “had limited effectiveness” because magazines are durable goods and tens of millions already existed — and that “an exemption for previously owned magazines would nearly eliminate any impact.” Now here’s the punchline: every state magazine ban on the books today contains exactly that exemption — including Massachusetts’ September 13, 1994 grandfather date.

And the most comprehensive neutral review in the country agrees. The RAND Corporation’s Gun Policy in America project, last updated January 2026, rates the evidence that these bans reduce violent crime as “inconclusive.” After thirty years and eight qualifying studies on mass shootings, the strongest rating RAND will assign is “limited evidence” — its second-weakest category.

Criminals Didn’t Get The Memo

A law only restricts the people who follow it. And the numbers on who actually follows magazine and registration laws are almost comical. This is not speculation — it’s the states’ own data, most of it pried loose through records requests they fought.

1. New York Attorney Paloma Capanna had to sue under the Freedom of Information Law just to get the SAFE Act numbers. The state’s own data, released in 2016: 44,485 assault weapons registered by 23,847 owners, against an estimated one million affected firearms — roughly 4% compliance. Total arrests statewide for failure to register over three years: eleven.
2. Connecticut The 2013 law produced 38,290 large-capacity magazine declarations — against a legislative-research-based estimate of more than 2.4 million such magazines in the state.
3. New Jersey When the state banned magazines over ten rounds in 2018, a records request to the State Police produced this answer from Sgt. Kristina Pados: “The gun owners of New Jersey have surrendered no magazines.”
4. Colorado After the 2013 magazine law, 55 of the state’s 62 sheriffs joined a lawsuit against it. Weld County Sheriff John Cooke held up two identical 30-round magazines — one grandfathered and legal, one not — and asked: “How is a deputy or an officer supposed to know which is which?”

And who actually holds the illegal guns? The Bureau of Justice Statistics surveyed prison inmates who possessed a firearm during their offense: 90% did not get it from a retail source. Forty-three percent got it off the street or from the underground market. These are not people filling out capacity-compliance paperwork, and no ten-round law touches the pipeline that arms them.

Massachusetts: A Case Study In Punishing The Wrong People

On paper, the Commonwealth’s law is ferocious. Unlicensed possession of a large-capacity feeding device under G.L. c. 269, § 10(m) carries two-and-a-half to ten years in state prison. In practice, the law is a two-tier system — and both tiers are wrong.

Start with the proof problem. The ban grandfathers anything lawfully possessed before September 13, 1994 — and Sheriff Cooke’s two-identical-magazines demonstration applies in full, because most magazines carry no date markings of any kind. Then, in 2018, the state’s highest court ruled in Commonwealth v. Cassidy that prosecutors must also prove the defendant knew the magazine held more than ten rounds. And the statute’s own text exempts FID-card holders from the mandatory minimum entirely.

Now look at what the Commonwealth will — and won’t — tell you about enforcement. The state filed roughly 2,816 large-capacity charges in 2022–2023, making § 10(m) one of the seven most common firearm charges in Massachusetts. Yet the state’s own legislatively mandated report contains no data at all on how those charges resolve. No conviction rates. No dismissal rates. Nothing. What we can see is telling: when the Suffolk County DA’s office touted a week of high-capacity arraignments in 2022 — calling the hardware “death machines” — the reported bail amounts were $7,500, $5,000, and $1,000. In 2025, WBUR reported that hundreds of cases, including weapons charges, were simply dismissed in Boston courts amid a public-defender shortage — one defendant was charged with murder weeks after his weapons case was dropped. Suffolk DA Kevin Hayden has acknowledged that a “fairly small group of repeat offenders” is driving illegal gun possession, and that “prior convictions and prior incarcerations have apparently done little to dissuade these individuals.”

Massachusetts’ own history closes the loop. After the state passed its sweeping 1998 gun law, gun homicides rose from 65 in 1998 to 122 in 2011, and Northeastern criminologist James Alan Fox noted that “a significant share of the guns that are used in crime in Massachusetts are purchased outside of Massachusetts and brought across the border.” Massachusetts is a low-crime state — but it was a low-crime state before these laws, and the criminals who remain are supplied by an interstate pipeline no magazine ban touches.

The Bans Didn’t Stop The Killers They Were Written For

These laws are sold as mass-shooting prevention. So check the record in the states that have them. The Buffalo supermarket shooter bought a New York-compliant rifle with a fixed 10-round magazine lock — then drilled the lock out and loaded 30-round magazines that were already illegal to possess in New York. The Monterey Park shooter killed eleven people in California using a 30-round magazine in a configuration illegal in the state. The Thousand Oaks shooter carried seven high-capacity magazines, all illegal in California.

Criminologist Gary Kleck’s review of mass shootings involving large-capacity magazines found that in every incident examined, the shooter carried multiple guns or multiple magazines anyway — and that a magazine change takes as little as two to four seconds. The ten-round line is not a wall between a madman and his victims. It never was. It’s a line only the law-abiding ever stand behind.

Meanwhile, The Person The Limit Actually Binds Is You

The one group that reliably obeys the ten-round line is the group the law was never aimed at: the licensed citizen defending a home or a family. Federal Judge Roger Benitez put it plainly in striking down California’s ban. A homeowner facing multiple intruders, in the dark, under adrenaline, with a miss rate that humbles trained officers, doesn’t get to ask the threat to pause while she reloads.

The courts are starting to catch up. In March 2025 the Ninth Circuit upheld California’s limit en banc — but in July 2026 the Third Circuit, sitting en banc, struck down New Jersey’s ten-round limit, splitting squarely with the Ninth. The Supreme Court has now granted review in two magazine-and-rifle-ban cases for the fall 2026 term, with Duncan waiting in the wings. The constitutional question these states have dodged for thirty years is finally on the docket.

The Sources Behind All Of This

We don’t expect you to take our word for any of it. Every claim above traces to a government report, a peer-reviewed study, a court decision, or the state’s own data. Read the primary sources.