Gun Control Laws: Federal Rules, Restrictions, and Penalties

Gun control laws in the United States operate on two levels. Federal law sets a nationwide floor: it defines who cannot possess a firearm, requires licensed dealers to run a background check on every sale, imposes extra scrutiny on a narrow class of weapons like machine guns and suppressors, and protects interstate transport under specific conditions. Each state then builds on that floor with its own rules on waiting periods, carry permits, banned features, and more. A state can be stricter than federal law. It cannot be looser.

What follows is what the federal rules actually require, who they apply to, and what happens when they are broken.

Who Cannot Legally Own a Firearm

Federal law lists specific categories of people who cannot possess or receive a firearm or ammunition, and these prohibitions apply regardless of what state law says. Under 18 U.S.C. § 922(g), the following people are barred:¹

Anyone convicted of a crime punishable by more than one year in prison, whether or not that sentence was actually imposed.
Fugitives from justice.
People who use or are addicted to controlled substances.
People a court has found mentally unfit, or who have been involuntarily committed to a mental institution.
Non-citizens in the country illegally, and, with limited exceptions, people on a nonimmigrant visa.
Servicemembers dishonorably discharged from the Armed Forces.
Former U.S. citizens who have renounced their citizenship.
People under qualifying domestic violence restraining orders that include a credible-threat finding or explicitly prohibit physical force against an intimate partner or child.
People convicted of a misdemeanor crime of domestic violence.

A prohibited person who possesses a firearm faces up to 15 years in federal prison. Someone with three or more prior convictions for violent felonies or serious drug offenses faces a mandatory minimum of 15 years.²

No state permit overrides these prohibitions. If federal law bars you, you are barred.

How Buying a Firearm Works Under Federal Law

How a purchase works depends almost entirely on whether the seller holds a Federal Firearms License.

Sales From Licensed Dealers

Every sale by a licensed dealer follows the same steps. The buyer completes ATF Form 4473, a questionnaire that requires identification and answers, under penalty of felony, to questions about whether the buyer falls into any prohibited category.³ Lying on this form carries up to five years in federal prison, even if the dealer catches the lie and refuses the sale.²

The dealer then runs the buyer through the National Instant Criminal Background Check System, managed by the FBI. NICS returns one of three results: Proceed, Deny, or Delay.⁴ A Proceed clears the sale. A Deny blocks it. A Delay means the FBI needs more time, and if no final determination arrives within three business days, the dealer may legally complete the transfer at their discretion. That three-day default is sometimes called the “Charleston loophole” after the 2015 church shooting, where a delayed check allowed a prohibited buyer to obtain a firearm.

For buyers between 18 and 20, the Bipartisan Safer Communities Act added an enhanced review. NICS examiners contact state juvenile justice agencies, state mental health agencies, and local law enforcement to search for disqualifying records that would not appear in the standard databases.⁵ This can turn up juvenile court findings, involuntary commitment records, and incident reports invisible to a standard check.

Private Sales

Federal law requires background checks only when the seller is a licensed dealer. Private individuals selling from a personal collection generally are not required to run a NICS check under federal law, but they are prohibited from selling to anyone they know or have reasonable cause to believe is a prohibited person.¹ Roughly a dozen states have enacted their own universal background check laws that close this gap for sales within their borders.

Age Requirements

Federal minimum ages differ by weapon and by seller. Licensed dealers cannot sell a handgun or handgun ammunition to anyone under 21, or a rifle, shotgun, or corresponding ammunition to anyone under 18.¹ For private sales, federal law sets a minimum of 18 for handguns and no minimum age for long guns. Several states have raised these floors, with some requiring buyers to be 21 for any firearm.

Weapons That Face Extra Federal Regulation

Ordinary rifles, shotguns, and handguns are regulated under the Gun Control Act. A narrower set of items falls under the National Firearms Act, which adds registration and approval requirements on top. NFA-regulated items include:⁶

Machine guns, meaning firearms that fire more than one round per trigger pull. Civilian transfers are limited to machine guns manufactured before May 19, 1986, which is why legal examples are scarce and expensive.
Short-barreled rifles, with a barrel shorter than 16 inches.
Short-barreled shotguns, with a barrel shorter than 18 inches.
Suppressors, sometimes called silencers.
Destructive devices, including grenades, bombs, and certain large-caliber weapons.
Any Other Weapons, a catch-all for concealable firearms that do not fit the other classes.

Acquiring an NFA item requires filing an application with the ATF, undergoing an additional background check, and paying a federal transfer tax. As of January 1, 2026, the transfer tax is $0 for suppressors, short-barreled rifles, short-barreled shotguns, and Any Other Weapons. Machine guns and destructive devices still carry the original $200 tax.⁷ Applications go through the ATF’s eForms system, and processing times run from weeks to several months.

Privately Manufactured Firearms

Privately made firearms without serial numbers, often called “ghost guns,” were brought further under the federal regulatory framework by a 2022 ATF rule that redefined “frame or receiver” to include partially complete firearm parts and “buy-build-shoot” kits. Under the rule, a licensed dealer who takes in a privately made firearm without a serial number must mark it with one before transferring it to a new owner and must run a NICS check before that transfer.⁸ A dealer who receives a ghost gun only to engrave a serial number and returns it to the same owner does not need to run a check.

Bump Stocks

Bump stocks, which allow a semiautomatic rifle to fire at a rate approaching that of a machine gun, were banned by an ATF rule in 2018. The Supreme Court struck that ban down in Garland v. Cargill in June 2024, holding that a semiautomatic rifle equipped with a bump stock does not meet the statutory definition of a machine gun because it does not fire more than one shot by a single function of the trigger.⁹ Bump stocks are no longer prohibited under federal law, though several states have their own bans.¹⁰

Carrying and Transporting Firearms Across State Lines

Rules for carrying a firearm on your person are overwhelmingly a matter of state law. Federal law contributes two things: a safe-passage provision for interstate travel, and a set of federally restricted locations that no state permit can override.

Interstate Transportation

Under 18 U.S.C. § 926A, a person who can legally possess a firearm at both their origin and destination may transport it through any state in between, provided the firearm is unloaded and neither the gun nor its ammunition is readily accessible from the passenger compartment. In a vehicle without a separate trunk, both must be in a locked container other than the glove compartment or console.¹¹ This protection is narrow. It covers transport, not extended stops. Spending the night in a restrictive state with your firearm in your hotel room is not the same as driving through it.

Federally Restricted Locations

Certain places are off-limits regardless of any state permit. Bringing a firearm into a federal building where government employees regularly work is punishable by up to one year in prison. Bringing one into a federal courthouse carries up to two years.¹² The Gun-Free School Zones Act prohibits possessing a firearm within 1,000 feet of any public or private school, with exceptions for people who hold a concealed carry permit issued by the state where the school is located and for firearms that are unloaded and in a locked container.¹³

Where State Law Changes the Answer

Federal rules are a floor. States can and do go further, and the variation is substantial enough that a firearm or accessory legal in one state can be a felony in a neighboring one.

Around a dozen states and the District of Columbia impose a mandatory waiting period between purchase and delivery, ranging from three to 14 days. Some cover only handguns; others cover all firearms. A handful of states restrict firearms with features associated with military-style weapons, such as pistol grips, adjustable stocks, or threaded barrels. Roughly 14 states also cap magazine capacity, most commonly at 10 rounds. Some states require a permit to purchase any firearm, not just to carry one, and a smaller number maintain registries of certain firearms.

On concealed carry, states fall into three broad camps. Shall-issue states must grant a permit to any applicant who meets objective criteria. May-issue states retain some discretion, though the Supreme Court’s 2022 Bruen decision sharply limited the ability of states to require applicants to show a special need for self-defense.¹⁴ The fastest-growing category is permitless carry, sometimes called constitutional carry. As of early 2026, 29 states allow eligible adults to carry a concealed handgun with no permit or training requirement. Most still let residents obtain a permit voluntarily, which can help with reciprocity when traveling.

Anyone moving or traveling with firearms should check the destination state’s rules directly rather than assume reciprocity.

Penalties for Federal Firearms Violations

Federal firearms penalties are steep and escalate with the seriousness of the offense.

False statements on Form 4473: up to five years in prison.²
Prohibited person in possession of a firearm: up to 15 years.²
Prohibited person with three prior violent-felony or serious drug convictions: a mandatory minimum of 15 years, with no possibility of a suspended sentence or probation.²
Firearm in a federal building: up to one year. In a federal courthouse: up to two years.¹²

These are federal maximums. Actual sentences depend on the facts, the defendant’s criminal history, and federal sentencing guidelines. State violations carry their own penalties on top of any federal charges, and the same conduct can be prosecuted in both systems.

The Constitutional Framework Behind These Laws

Every federal and state gun regulation exists against the Second Amendment, which the Supreme Court has interpreted three times in the modern era.

In District of Columbia v. Heller (2008), the Court held that the Second Amendment “protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home.”¹⁵ The Court also said the right is not unlimited, describing regulations on commercial sales, bans on carrying in sensitive places, and prohibitions on possession by felons and the mentally ill as “presumptively lawful.”

In New York State Rifle & Pistol Association v. Bruen (2022), the Court extended that individual right beyond the home and required courts evaluating gun laws to ask whether a regulation is “consistent with this Nation’s historical tradition of firearm regulation.”¹⁴ That test has forced lower courts to re-examine dozens of existing gun laws.

In United States v. Rahimi (2024), the Court upheld the federal ban on firearm possession by someone under a domestic violence restraining order, concluding that “an individual found by a court to pose a credible threat to the physical safety of another may be temporarily disarmed consistent with the Second Amendment.”¹⁶ Rahimi clarified that Bruen‘s historical-tradition test does not require a modern law to have an exact historical twin, only a comparable historical principle.

The practical effect is that many federal rules described above rest on legal ground that has shifted twice in the last two decades and continues to be tested in lower courts. If you are relying on a specific rule for a specific plan, confirm the current state of the law before acting.

1
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
2
Office of the Law Revision Counsel. 18 USC 924 – Penalties
3
Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms Transaction Record – ATF Form 4473
4
Bureau of Alcohol, Tobacco, Firearms and Explosives. Federal Firearms Licensee Quick Reference and Best Practices Guide
5
Federal Bureau of Investigation. NICS Enhanced Background Checks for Under-21 Gun Buyers Showing Results
6
Bureau of Alcohol, Tobacco, Firearms and Explosives. Chapter 2 – What Are Firearms Under the NFA
7
Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transfer and Register NFA Firearm – Form 4
8
Bureau of Alcohol, Tobacco, Firearms and Explosives. Definition of Frame or Receiver and Identification of Firearms
9
Supreme Court of the United States. Garland v. Cargill, No. 22-976 (2024)
10
Bureau of Alcohol, Tobacco, Firearms and Explosives. Bump Stocks
11
Office of the Law Revision Counsel. 18 USC 926A – Interstate Transportation of Firearms
12
Office of the Law Revision Counsel. 18 USC 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities
13
Office of Justice Programs. Gun-Free School Zones Act of 1990
14
Supreme Court of the United States. New York State Rifle and Pistol Association v. Bruen, No. 20-843 (2022)
15
Justia Law. District of Columbia v. Heller, 554 U.S. 570 (2008)
16
Supreme Court of the United States. United States v. Rahimi, No. 22-915 (2024)