What Is the Firearms Owners Protection Act (FOPA)?

The Firearms Owners Protection Act, passed in 1986 and often called FOPA, is a federal law that rewrote significant parts of the Gun Control Act of 1968. It tightened some restrictions, loosened others, and added new protections for individual gun owners. Its most consequential pieces are a safe-harbor rule for transporting firearms across state lines, a ban on civilian possession of machine guns made after May 19, 1986, restrictions on armor-piercing ammunition, a prohibition on any federal firearms registry, and revised rules for who counts as a firearms dealer.

Interstate Transportation Safe Harbor

The most practically useful part of the law for ordinary gun owners is 18 U.S.C. § 926A. You can transport a firearm from any place where you may lawfully possess and carry it to any other place where you may lawfully possess and carry it, even if the route runs through a state with stricter gun laws. The firearm must stay unloaded for the entire trip, and neither the gun nor any ammunition can be readily accessible from the passenger compartment of your vehicle.¹

If your vehicle has a trunk, putting the unloaded firearm and ammunition there satisfies the rule. In vehicles without a separate compartment, like SUVs, hatchbacks, or pickups, you need a locked container. The glove compartment and center console don’t qualify, even if they lock.¹

The protection only applies when you can lawfully possess the firearm at both ends of the trip. It also assumes continuous travel. A gas or meal stop is fine; an overnight stay for sightseeing in a state where you couldn’t legally possess the gun puts you outside the statute.

It’s a Defense, Not Immunity From Arrest

Section 926A doesn’t stop police from arresting you. Federal courts, including the Second Circuit, have treated the safe harbor as an affirmative defense you raise in court, not a shield against a stop or detention. If a local officer has probable cause to believe you’ve violated state weapons law, you can be arrested, and whether you actually met the § 926A conditions gets litigated later. That gap matters most in states that aggressively enforce their firearms laws, where travelers have been arrested at airports and highway stops despite believing they were in compliance.

The Hughes Amendment: Machine Gun Ban

The most contentious piece of the 1986 law is what’s usually called the Hughes Amendment, codified at 18 U.S.C. § 922(o). It makes it illegal for any civilian to transfer or possess a machine gun, with one narrow exception: machine guns that were lawfully possessed before May 19, 1986.²

Federal law defines a machine gun as any weapon that fires more than one shot automatically with a single trigger pull, without manual reloading. The definition also reaches the receiver of such a weapon and parts designed solely to convert a standard firearm into one.³

Pre-1986 machine guns registered under the National Firearms Act before the cutoff can still be owned and transferred between civilians, provided the owner has the correct NFA tax stamp and paperwork. Anything manufactured or added to the registry after that date is limited to government agencies, law enforcement, and authorized dealer samples. Violating the ban carries up to ten years in federal prison, a fine, or both.⁴

Because the transferable supply was frozen in 1986 and can only shrink, prices for legally transferable machine guns now run into the tens and sometimes hundreds of thousands of dollars. The financial barrier alone puts legal machine gun ownership out of reach for most people.

Armor-Piercing Ammunition

FOPA added the first federal restrictions on armor-piercing handgun ammunition. The law defines it two ways: a projectile or core made entirely of hard metals like tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium that can be used in a handgun; or a full-jacketed handgun projectile larger than .22 caliber whose jacket is more than 25 percent of the total weight.⁵

Manufacturing, importing, and selling armor-piercing ammunition is generally illegal unless the rounds are produced for government or law enforcement use, for export, or for testing authorized by the Attorney General.² Several categories fall outside the definition entirely: shotgun shot required by hunting regulations, frangible target projectiles, projectiles the Attorney General determines are primarily for sporting purposes, and industrial charges used for things like oil and gas well perforation.

Using or carrying armor-piercing ammunition during a federal violent crime or drug trafficking offense adds a mandatory minimum of five years on top of the sentence for the underlying crime.⁶

No Federal Firearms Registry

FOPA drew a hard line against centralized government tracking of gun ownership. Under 18 U.S.C. § 926, no federal regulation issued after the act may require firearms transaction records to be transferred to a government-controlled facility, and no system of registration covering firearms, their owners, or transactions may be created.⁷

Licensed dealers still keep transaction logs, but those records stay at the dealer’s premises. The ATF can’t consolidate them into a searchable federal database, and federal agents can access a dealer’s records only under limited circumstances, mostly criminal investigations. When a dealer goes out of business, the records go to the ATF’s Out-of-Business Records Center within 30 days, or to a successor licensee if the business is being taken over.⁸

Who Counts as a Dealer

The act reshaped the rules for Federal Firearms Licenses, aiming to ease pressure on casual sellers while keeping oversight of commercial dealers. Federal law distinguishes people who are “engaged in the business” of selling firearms from those who occasionally buy, sell, or trade from a personal collection. Only the first group needs an FFL. Someone is engaged in the business if they devote regular time and effort to buying and reselling firearms with the primary goal of making money. Occasional sales to improve a personal collection, liquidate inherited firearms, or trade with family members do not trigger the licensing requirement.⁵

A 2024 ATF rule added rebuttable presumptions to help draw that line. Repeatedly reselling guns within 30 days of purchase, repeatedly selling new-in-box guns of the same model within a year, or renting vendor space at gun shows to display firearms for sale can each raise a presumption of dealing. The presumptions apply in civil and administrative proceedings, and the seller can present evidence to rebut them.⁹

Inspection Limits

FOPA also caps how often the ATF can run routine compliance inspections of licensed dealers. For general record-keeping checks, agents are limited to one inspection during any 12-month period. That cap doesn’t apply when the inspection traces a specific firearm connected to a criminal case or is part of a criminal investigation of someone other than the dealer.¹⁰

The Willful Violation Standard

The act raised the bar for revoking an FFL. To strip a license, the government must show a willful violation of federal firearms law. Federal courts read “willful” here as intentional disregard of a known legal duty, or plain indifference to legal obligations. A good-faith paperwork mistake generally doesn’t clear that bar. Even so, a single willful violation is enough for revocation.¹¹

Ammunition Sales

Before FOPA, buying ammunition was paperwork-heavy. Sellers had to record the buyer’s name, address, and age on every purchase. The 1986 act eliminated that requirement for most ammunition sales and restored the ability to buy ammunition through mail order, which the Gun Control Act of 1968 had cut off. These changes apply at the federal level only. Some states have since enacted their own ammunition purchase requirements, including background checks or point-of-sale records.

1
Office of the Law Revision Counsel. 18 USC 926A – Interstate Transportation of Firearms
2
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
3
Office of the Law Revision Counsel. 26 USC 5845 – Definitions
4
Office of the Law Revision Counsel. 18 USC 924 – Penalties
5
Office of the Law Revision Counsel. 18 USC 921 – Definitions
6
Office of the Law Revision Counsel. 18 USC 929 – Use of Restricted Ammunition
7
Office of the Law Revision Counsel. 18 USC 926 – Rules and Regulations
8
Bureau of Alcohol, Tobacco, Firearms and Explosives. 27 CFR 478.127 – Discontinuance of Business
9
Federal Register. Definition of Engaged in the Business as a Dealer in Firearms
10
Office of the Law Revision Counsel. 18 USC 923 – Licensing
11
Bureau of Alcohol, Tobacco, Firearms and Explosives. Revocation of Firearms Licenses