If agents tell you your gun is unregistered, they are talking about one federal list, not about state paperwork, a bill of sale, or a background check. Federal law keeps a central record of certain heavily regulated weapons, and the charge in most cases is simple to state: you received or possessed one of those weapons, and that record does not show it registered to you. This page explains how that record works, what the government must prove, what punishment the law allows, and where a defense begins. It sits within our overview of Federal Firearms Charges, and a companion page covers NFA firearms as a whole.
How lawful registration is supposed to work
The registration system lives in 26 U.S.C. 5841. The law orders the Secretary to keep a central list: "The Secretary shall maintain a central registry of all firearms in the United States which are not in the possession or under the control of the United States." Then it gives the list its name: "This registry shall be known as the National Firearms Registration and Transfer Record." Every unregistered firearm case turns on what that Record shows.
The Record tracks three things for each weapon: identification of the firearm, the date of registration, and the identification and address of the person entitled to possession. Registration is not a one time event that attaches to the weapon forever. It attaches to a person. The statute says so directly: "Each firearm transferred shall be registered to the transferee by the transferor." When a regulated weapon changes hands, the seller is the one who must put the buyer on the Record, through an approved transfer, before the buyer takes it.
A lawful transfer has a fixed sequence, set out in 26 U.S.C. 5812. It starts with paperwork: "A firearm shall not be transferred unless (1) the transferor of the firearm has filed with the Secretary a written application, in duplicate, for the transfer and registration of the firearm to the transferee." The application must identify the transferor, the weapon, and the transferee, and where the transferee is an individual the identification must include fingerprints and a photograph. Any transfer tax due must be paid, shown by the proper stamp on the original application. And the transfer is not lawful when the papers are filed. It is lawful when the government says yes: the application must show "that the Secretary has approved the transfer and the registration of the firearm to the transferee." The timing rule is absolute: "The transferee of a firearm shall not take possession of the firearm unless the Secretary has approved the transfer and registration of the firearm to the transferee." Taking the weapon during the waiting period violates the law even if approval later arrives.
Two further points complete the picture. First, some applications must be denied. The statute provides that "Applications shall be denied if the transfer, receipt, or possession of the firearm would place the transferee in violation of law." A person barred from possessing the weapon cannot cure the problem with paperwork. Second, the transfer tax is set by 26 U.S.C. 5811. The current text imposes "$200 for each firearm transferred in the case of a machinegun or a destructive device" and "$0 for any firearm transferred which is not described in paragraph (1)." The tax is paid by the transferor. Tax mechanics matter less to most defendants than the approval sequence, but they explain why lawful transfers leave a paper trail of stamps and approved forms that investigators check first.
One practical consequence follows. A person who lawfully possesses a registered weapon must keep proof: "A person possessing a firearm registered as required by this section shall retain proof of registration which shall be made available to the Secretary upon request." If you hold an approved transfer, keep the approved form where you can find it, and show it to your lawyer before you show it to anyone else.
The charge: what the government must prove
The criminal statute, 26 U.S.C. 5861, opens with a flat ban: "It shall be unlawful for any person" to do any of twelve listed things. Most prosecutions for simple possession rest on one of them, subsection (d): "to receive or possess a firearm which is not registered to him in the National Firearms Registration and Transfer Record."
The Ninth Circuit's model jury instructions break subsection (d) into three elements the government must prove beyond a reasonable doubt. First, the defendant knowingly possessed or received the weapon. Second, the defendant was aware of the features or characteristics that bring the weapon within the statute, such as a short barrel or a silencer. Third, the weapon was not registered to the defendant in the National Firearms Registration and Transfer Record. The same instruction adds a limit that surprises many readers: "The government need not prove that the defendant knew that possessing the firearm was illegal." Knowledge of the object matters. Knowledge of the law does not.
The knowledge point deserves emphasis because it is the main trial defense in these cases. The Justice Department's own policy, adopted after the Supreme Court's Staples decision, is that "the government must prove that the defendant knew the features of the firearm that brought it within the scope of the Act." That policy applies in every case prosecuted under the National Firearms Act, not only machinegun cases. A person who genuinely did not know the barrel was short, did not know a device worked as a silencer, or did not know the parts in the box met the legal definition has an attack on the second element. But no one should confuse this with ignorance of the registration rule itself, which the government does not have to prove.
Subsection (d) is the charge most readers face, but the neighboring subsections explain how one transaction can produce several counts. Receiving or possessing a weapon that someone else transferred illegally is subsection (b): "to receive or possess a firearm transferred to him in violation of the provisions of this chapter." Receiving or possessing a weapon that someone made illegally is subsection (c): "to receive or possess a firearm made in violation of the provisions of this chapter." Possessing a weapon with no serial number is subsection (i): "to receive or possess a firearm which is not identified by a serial number as required by this chapter." Moving an unregistered weapon across state lines adds subsection (j): "to transport, deliver, or receive any firearm in interstate commerce which has not been registered as required by this chapter." And the other side of the table faces its own liability: transferring in violation of the rules is subsection (e), "to transfer a firearm in violation of the provisions of this chapter," while making one is subsection (f), "to make a firearm in violation of the provisions of this chapter." False paperwork is subsection (l): "to make, or cause the making of, a false entry on any application, return, or record required by this chapter, knowing such entry to be false."
Notice what subsection (d) does not require. It has no interstate commerce element. Unlike many federal gun charges, the government does not have to prove the weapon traveled in or affected commerce. It proves knowing possession, knowledge of the regulated features, and the state of the Record. That missing element is one reason these cases can be simpler for the government to charge than they look, and it is why the defense usually concentrates on the weapon and the paperwork rather than on where the gun has been.
Which weapons count under § 5845(a), and which do not
The word firearm in this chapter does not mean what it means in ordinary speech. It means only the eight categories in 26 U.S.C. 5845(a): short barreled shotguns, weapons made from shotguns, short barreled rifles, weapons made from rifles, any other weapon, machineguns, silencers, and destructive devices. An ordinary hunting rifle or handgun is not covered no matter how it was bought. The legal lines are exact: "a shotgun having a barrel or barrels of less than 18 inches in length" and "a rifle having a barrel or barrels of less than 16 inches in length." Weapons made from them count where the modified weapon is under 26 inches overall or keeps a short barrel. The catchall, any other weapon, reaches concealable weapons such as "any weapon or device capable of being concealed on the person from which a shot can be discharged through the energy of an explosive," with stated exclusions for ordinary pistols and revolvers with rifled bores and for weapons designed to be fired from the shoulder that cannot fire fixed ammunition.
One exclusion removes a whole class of objects from the law. Antique firearms are out. The definition covers older weapons and replicas with antique ignition systems, plus pre-1899 fixed ammunition firearms whose ammunition is no longer made here and is not readily available in ordinary trade. An unserviceable firearm, one that cannot fire and cannot readily be restored to firing condition, is not excluded. The law does let it be transferred as a curio or ornament without paying the transfer tax. A rusted relic that cannot fire is still treated as a firearm under this chapter unless it fits the antique definition.
These definitions decide cases. Measurement fights over barrel length, disputes over whether a device functions as a silencer, arguments over whether parts on hand meet the machinegun definition, and expert battles over operability and ready restoration are the substance of litigating what the object is. Preserve the weapon exactly as found and let counsel test the government's proof. Do not alter, repair, or surrender the item for informal testing without legal advice, because each of those steps can destroy the very issue that might defeat the charge.
Prison time and fines under § 5871, and forfeiture
Every violation of this chapter carries the same statutory penalty. Under 26 U.S.C. 5871, "Any person who violates or fails to comply with any provision of this chapter shall, upon conviction, be fined not more than $10,000, or be imprisoned not more than ten years, or both." There is no mandatory minimum anywhere in this penalty section, so probation is legally possible in an appropriate case and the judge sets the sentence within the ten year ceiling.
Conviction also costs the weapon. Under 26 U.S.C. 5872, "Any firearm involved in any violation of the provisions of this chapter shall be subject to seizure and forfeiture." Forfeited firearms are not auctioned back. The statute provides that "no such firearm shall be sold at public sale," and where there is no remission or mitigation the weapon is destroyed or retained officially. Forfeiture follows the gun regardless of how the prison portion of the sentence comes out.
One more provision protects people who try to comply. Under 26 U.S.C. 5848, information from an application, registration, or required records generally may not "be used, directly or indirectly, as evidence against that person in a criminal proceeding" for a violation that occurred before or at the same time as the filing. The exception matters: the protection does not cover prosecutions for furnishing false information. Honest compliance paperwork gets a shield. False paperwork gets a new charge.
Read these numbers for what they are: statutory maximums, not predictions. No page can tell you what any particular person will receive. The real sentence depends on the guideline calculation, the facts of the case, the criminal history, and the judge. The facts of a case change everything. Background on how judges move from statutes to sentences is on our page about federal sentencing.
How the guidelines score an unregistered firearm case
The 2025 Guidelines Manual sends every subsection of this statute to one guideline. Its Statutory Index maps "26 U.S.C. § 5861(a)–(l)" to section 2K2.1, titled Unlawful Receipt, Possession, or Transportation of Firearms or Ammunition; Prohibited Transactions Involving Firearms or Ammunition. The penalty provision maps there too. That section then sets the starting level and the adjustments.
The starting level for an ordinary unregistered possession case is fixed by the weapon itself: "(5) 18, if the offense involved a firearm described in 26 U.S.C. § 5845(a)." Every weapon on the regulated list triggers this starting point, so most subsection (d) cases begin at level 18 before any adjustment. Prior convictions can push the start higher. Two prior felony convictions for a crime of violence or a controlled substance offense start the case at level 26 where the weapon is on the regulated list, and one such conviction starts it at level 22, with lower combinations reaching level 20 or 24 depending on the exact mix of priors and weapon type.
Then the specific offense characteristics adjust the level based on what actually happened. Several matter often in registration cases:
- Number of weapons. Three or more firearms add levels on a sliding scale, from 2 levels for three to seven weapons up to 10 levels for two hundred or more.
- Destructive devices. A portable rocket, missile, or launcher adds "increase by 15 levels," while any other destructive device adds "increase by 2 levels." These devices start at the regulated weapon base level and then stack this enhancement on top.
- Serial numbers. A stolen weapon adds 2 levels. A weapon with a serial number altered so the original information is "rendered illegible or unrecognizable to the unaided eye" adds 4 levels, as does knowing possession of a weapon with no serial number at all. Because most registration cases start above the low regulatory base levels, these enhancements apply in full here.
- Connection to other crime. Possessing or transferring the weapon with knowledge, intent, or reason to believe it would be used in connection with another felony adds 4 levels: "increase by 4 levels. If the resulting offense level is less than level 18, increase to level 18." In a case that already starts at 18, this enhancement still adds its 4 levels.
- Cross reference. Where the weapon was used or possessed in connection with another offense, or transferred knowing or intending it would be so used, the guideline for that other offense applies "if the resulting offense level is greater than that determined above." Where death resulted, the most analogous homicide guideline can apply instead. This is how a registration case tied to violence can be sentenced as something far more serious than a paperwork case.
One mitigation argument available in ordinary gun cases is closed here. The guidelines allow a reduction to level 6 for a person who possessed everything solely for lawful sporting purposes or collection, but the commentary states the limit plainly: "where the base offense level is determined under subsections (a)(1)–(a)(5), subsection (b)(2) is not applicable." Because registration cases start at level 18 under subsection (a)(5), that sporting and collection reduction is unavailable. Do not assume a collector profile lowers the guideline range. It may still matter at sentencing as a variance argument, but it does not change the calculation.
The closest neighbor charges, and why the distinction matters
Three nearby charges cover similar ground, and telling them apart is part of defending any one of them.
The first neighbor is felon in possession under 18 U.S.C. 922(g). That statute punishes possession based on who you are: a convicted felon, a fugitive, an unlawful drug user, a person committed to a mental institution, and several other listed statuses. Its core reads: "to ship or transport in interstate or foreign commerce, or possess in or affecting commerce, any firearm or ammunition." Two differences stand out. The status charge requires the commerce link that subsection (d) omits, and it applies to any firearm, while subsection (d) applies only to regulated weapons. The penalties differ as well. A knowing violation of the status provision carries up to fifteen years: "Whoever knowingly violates subsection (d) or (g) of section 922 shall be fined under this title, imprisoned for not more than 15 years, or both." Where both charges arise from one gun, each must be proved on its own elements, and counsel should test whether the facts fit the count charged.
The second neighbor is machinegun possession under 18 U.S.C. 922(o), which provides that "it shall be unlawful for any person to transfer or possess a machinegun." A machinegun that is not registered to its possessor can look like both a subsection (d) case and a section 922(o) case. Department policy resolves the overlap by date. Because the government stopped registering machineguns made after May 19, 1986, compliance with the registration rules is impossible for those weapons, and the Justice Manual directs that "prosecutors should charge the unlawful possession or transfer of a machinegun made after May 19, 1986 under § 922(o)." A knowing violation of that provision carries up to ten years: "Whoever knowingly violates subsection (a)(6), (h), (i), (j), or (o) of section 922 shall be fined as provided in this title, imprisoned not more than 10 years, or both." Our page on machinegun charges covers that offense in full, and the difference decides charging fights: pre-1986 registered machineguns live in the NFA system, while post-1986 machineguns live under section 922(o).
The third neighbor sits inside the same statute: transfer versus possession. Subsection (e) punishes the person who passes the weapon along in violation of the rules, while subsection (d) punishes the person who receives or holds it unregistered. One transaction can therefore expose the seller and the buyer to different subsections with different proof. The seller's defense attacks the transfer rules. The buyer's defense attacks possession, knowledge, and the Record. Related status issues, where a prior conviction bars possession entirely, are covered on our page about felon in possession.
Defenses that arise under this charge
Every case turns on its facts, but the defenses below come straight from the elements and definitions above:
- You did not know the regulated features. The government must prove awareness of the characteristics that bring the weapon within the law. An inherited gun stored for years, a barrel length you never measured, a device you did not know functioned as a silencer, or parts whose legal significance you did not grasp all attack the knowledge element the Ninth Circuit's model instructions require.
- The weapon is not on the regulated list. If the barrel measures at or above the legal line, if the device does not function as charged, if the parts do not meet the statutory definition, or if the object is an antique, the charge fails at the threshold. Measurement and operability evidence, often through experts, is the battleground.
- The Record is wrong or incomplete. The government proves its case from the National Firearms Registration and Transfer Record, and records can be wrong. A timely approved transfer the system failed to reflect, a registration under a prior name, or confusion between similar serial numbers can each break the chain. Demand the actual Record evidence, not an agent's summary of it.
- Possession is not proved. Momentary handling, a weapon found in a shared space, or access without control may not amount to possession. The government must prove you knowingly possessed or received the specific weapon, and constructive possession fights over shared homes, vehicles, and storage units are common.
- Your own paperwork cannot be used. Where investigators built the case from your compliance filings, the use restriction in section 5848 may bar that evidence for violations that predate or coincide with the filing. This argument has a false statement exception and fact specific limits, so raise it early through counsel.
- The wrong statute for the facts. Where the proof shows a status problem but no registration problem, or a post-1986 machinegun charged as an NFA violation, the defense is that the elements of the charged provision are not met even if some other law might have been. The neighbor distinctions above are the map for this argument.
- Guideline disputes. The number of weapons attributed, whether the destructive device enhancement fits, whether the serial number finding is supported, whether the connection to another crime is proved, and whether the cross reference to a more serious offense is justified can each move the range by years. These fights happen at sentencing and deserve the same preparation as trial issues.
If agents are asking about your weapon
Do not try to fix the paperwork on your own. Registering, modifying, moving, or hiding the weapon after the fact does not erase the earlier possession the charge is based on, and each of those steps can create a new crime, from unlawful making to false entries to obstruction. Do not file forms, call the agency, consent to searches, or explain the weapon's history without counsel. If agents have already visited, write down exactly what was said while it is fresh and bring that account, with any transfer forms and stamps you hold, to a lawyer experienced in federal firearms cases. Most ATF investigations in this area start with the Record and end with an interview, so what you say after contact often matters more than what happened before it.