Written by Ethan Viator, Lex Tecnica Law Clerk
The term “Arm” in the context of Second Amendment jurisprudence has been defined and redefined; while pedantic, any definition carries the potential of massive legal change. The Supreme Court in District of Columbia v. Heller, 554 U.S. 570 (2008), cited two period definitions: “The 1773 edition of Samuel Johnson’s dictionary defined ‘arms’ as ‘[w]eapons of offence, or armour of defence.’ Timothy Cunningham’s important 1771 legal dictionary defined ‘arms’ as ‘any thing that a man wears for his defence, or takes into his hands, or useth in wrath to cast at or strike another.’” This leaves us with some important answers, but a slew of questions. The one on the forefront of my mind is, what about firearm attachments like suppressors?
A firearm attachment is not used in wrath to cast at another, but a definition of arms that excludes attachments would make it possible to degrade the right to keep and bear arms into no right at all. If the only thing the Second Amendment protects are components that are strictly necessary for a firearm to function then you do not have the right to a rifled barrel, a scope, a magazine for storing ammunition, a stock to comfortably fire the weapon, a trigger, cased ammunition, suppressors, and almost any other component you could even try to name. The right to keep and bear arms must apply to firearms attachments that are not strictly necessary for the firearm to function.
What Are Suppressors?
Suppressors are a firearm safety device. When hot gases leave the barrel of a firearm, they move quickly and are extremely hot. This hot, fast-moving gas plays a large part in the audible “BANG” expelled from a firearm when a trigger is pulled. This explosive sound is dangerous not only to the person who has fired a firearm, but any onlookers, observers, and anyone nearby. Even though almost all shooters actively use hearing protection when using firearms, many long-time shooters find themselves with hearing loss, and shooters of certain firearms even find themselves with other physical injuries. These injuries are often related to the fine bones and tissues of the inner ear, but certain unsuppressed firearms even carry the potential risk of causing permanent brain injuries when used for long periods of time. See Bharani Thangavelu et al., Overpressure Exposure from .50-Caliber Rifle Training Is Associated with Increased Amyloid Beta Peptides in Serum, 11 Frontiers in Neurology, art. 620 (2020), https://pmc.ncbi.nlm.nih.gov/articles/PMC7396645/. The suppressor is a device, which when attached to the end of a firearm’s barrel, briefly captures and slows the violent release of gases from the firearm. Instead of the hot gases being violently expelled from the barrel of the firearm faster than the speed of sound, they are slowed by the internal components of a suppressor to the point that when exiting the device, the sound of the bullet’s explosive charge is greatly diminished. Most firearms remain too loud to be safely fired with no hearing protection, but instead of a rifle causing your ears to ring through hearing protection equipment, most suppressed rifles are made quiet enough for the sound to be much more comfortable.
Hollywood has portrayed firearms suppressors to be the tools of assassins, able to make a firearm so quiet that a murderer could shoot somebody in a crowd and still be undetected. This exaggeration has caused many unfamiliar with firearms to re-classify the suppressor from “safety device” to “murder device”. There are few firearms that allow for a suppressor to truly make them quiet, and those firearms are often shooting bullets which themselves are specifically made to travel slower than the speed of sound. The overwhelming majority of suppressed firearms remain loud enough, while suppressed, to cause permanent hearing damage to anyone in the vicinity of the weapon. They make a weapon quieter; they do not make a weapon silent.
Why Are Suppressors Arms?
With the purpose of a suppressor established, the question becomes whether the Second Amendment protects it. Two reasons say it does.
Bans and restrictions on suppressors are bans and restrictions on firearms which are made and intended to be suppressed. The Supreme Court told us in New York State Rifle & Pistol Ass’n v. Bruen, 597 U.S. 1 (2022) that when a law places a burden on the Second Amendment, namely the right to keep and bear arms, the State or Federal government must prove that their law comports with our nation’s history and tradition of firearms regulation by providing evidence that the law enacts a type of burden on the Second Amendment that is relevantly similar to a burden that was in place at the time of the founding of our nation. We also know from this Supreme Court that bans on firearms which are not dangerous and unusual or are in common use for lawful purposes are unconstitutional. By banning or restricting access to suppressors, firearms which are designed and intended to be fired suppressed are also banned and restricted. The type of firearm which is being banned and restricted are firearms which are in common use for lawful purposes. According to ATF data there are more than 6,900,000 suppressors legally owned and registered in the United States. Bureau of Alcohol, Tobacco, Firearms & Explosives, Current Processing Times (Sept. 29, 2026), https://www.atf.gov/resource-center/current-processing-times (reporting 6,905,213 registered silencers as of September 3, 2026). Even if one were to successfully argue that suppressed firearms are dangerous, one could not also argue that they are unusual. “[T]his is a conjunctive test: A weapon may not be banned unless it is both dangerous and unusual…”. Caetano v. Massachusetts, 577 U.S. 411, 417 (2016) (Alito, J., concurring in the judgment). Because burdening suppressor ownership burdens ownership of firearms which are not dangerous and unusual, and are in common use for lawful purposes, burdening suppressor ownership facially implicates the Second Amendment. The government should have to justify restrictions on suppressors rather than avoid constitutional scrutiny by labeling them accessories. That is a reason to recognize constitutional protection for suppressors.
An understanding of the Second Amendment that refuses to acknowledge firearm attachments which are not strictly necessary for a firearm to function, renders the Second Amendment meaningless. The most basic construction of a firearm could be a metal tube with a hole in the back for somebody to strike the primer of the bullet with a nail and a hole in the front for the bullet to be ejected from. It could be a metal tube with a hole in the front and a spot to put a fuse to ignite black powder. In order to have a device which ejects a projectile towards a target using the force of an explosion, you do not need a stock. A stock just makes the weapon safer and more accurate. You do not need a rifled barrel. A rifled barrel just makes a firearm safer and more accurate. You do not need a suppressor. A suppressor just makes a weapon quieter and safer to use. By refusing to acknowledge firearms attachments and components as deserving of Second Amendment protections, the only protected components of a firearm would be the existence of a chamber to hold a charge and projectile. In order for the Second Amendment to matter, firearms attachments must be protected.
The Courts:
Even within the same circuits, courts have disagreed about whether suppressors are arms deserving of Second Amendment protection. The Fifth Circuit Court of Appeals in Peterson and Comeaux has provided diametrically opposed answers to this question, “While a suppressor might prove useful to one casting or striking at another, that usefulness does not transform a gas dissipater into a bullet caster. Instead, we agree with the Tenth Circuit that a suppressor ‘is a firearm accessory . . . not a weapon.’” United States v. Peterson, 127 F.4th 941, 946 (5th Cir. 2025) (quoting United States v. Cox, 906 F.3d 1170, 1186 (10th Cir. 2018)).
In 2025, the Fifth Circuit Court of Appeals withdrew their original Peterson decision. After the Department of Justice under the 2nd Trump administration conceded that firearms suppressors were arms protected by the Second Amendment, the court stated, “we assume without deciding that suppressors constitute “arms” under the Second Amendment, as both parties now contend.” United States v. Peterson, 161 F.4th 331, 339 (5th Cir. 2025). Instead of diving into the issue of whether suppressors were protected arms, the court was able to avoid the issue because both the Plaintiff and the Defendant agreed that suppressors were protected arms. Instead of deciding that suppressors were protected by the Second Amendment, the court only assumed they were for the purposes of resolving Peterson.
The Fifth Circuit Court of Appeals has also affirmed that suppressors are arms protected by the second amendment on different grounds:
Silencers lead to “reduced loudness (and reduced risk of hearing loss), lower recoil from the firearm, elimination of muzzle blast, increased accuracy, and faster follow-up shots.” Those are all critical functions that make firearms both safer and more effective for their core lawful purpose of self-defense. Because silencers are used in self-defense “to cast at or strike another,” they are Second Amendment “Arms.”
United States v. Comeaux, 179 F.4th 297, 301 (5th Cir. 2026) (footnote omitted).
The same court has said that suppressors are not arms, that they may be arms, and that they are arms. Even within the same circuits, the protections, if any, that suppressors are owed continue to be in flux.
Conclusion:
Whether the courts will affirm that suppressors are owed protection is a question on the cutting edge of firearms law. Suppressors must be protected by the Second Amendment. They are “arms.” They are not arms because they are used as weapons by themselves, they are arms because an understanding of the Second Amendment that excludes them excludes everything.
This article has been reviewed and approved for legal accuracy by Scott Whitworth, Esq. It is intended for informational purposes only and does not constitute legal advice.
