A silencer, or sound suppressor, is a device that reduces a firearm’s sound signature, or report, and eliminates its muzzle flash, making it difficult to determine where a shot originated. The devices work like car mufflers, allowing the hot gases that propel bullets to expand and cool down before they hit the air outside of the gun, reducing the loud “pop” that normally comes with every gunshot.
After being invented in the early 1900s, silencers were quickly used in high-profile crimes, leading Congress to enact the National Firearms Act (NFA) of 1934, which imposed strict registration requirements on silencers and other dangerous weapons, including machine guns and short-barreled rifles and shotguns. The NFA requires that civilians interested in building or purchasing silencers first submit an application to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) along with their fingerprints, a passport-style photo, and a $200 tax stamp before undergoing an enhanced background check. Only after being approved by the ATF can someone take possession of an NFA item.
The ATF notes that the NFA application process was designed “to curtail, if not prohibit, transactions in NFA firearms,” and the $200 tax “was considered quite severe and adequate to carry out Congress’ purpose to discourage or eliminate transactions in these firearms” in 1934. But the tax — roughly $4,600 in today’s dollars — has not been raised or adjusted for inflation since 1934.
the gun industry’s push for silencers
Silencers are just as dangerous today as when they were first invented, as evidenced by their use in mass shootings — like the 2023 Monterey Park shooting and the 2019 Virginia Beach shooting, where one survivor said the attacker’s suppressed firearm sounded like a nail gun, leading to more deaths: “If it was a regular gunshot, we would’ve definitely known a lot sooner, even if we would’ve had 30 or 60 seconds more. I think we could’ve all secured ourselves…all of us could’ve barricaded ourselves in.”
Yet groups like the National Rifle Association, American Suppressor Association, and National Shooting Sports Foundation (NSSF) — the gun industry’s trade association — have pushed for bills that would remove silencers from NFA regulations and allow them to be sold and transferred like any other weapon, as well as state laws relaxing silencer restrictions. These efforts are often branded as protecting the hearing of hunters and shooters, but silencer-equipped firearms can still cause permanent hearing damage without proper protection, such as earplugs or earmuffs.
Silencer retailers have also streamlined the silencer-buying process by preparing NFA applications for customers, for example, and setting up “NFA trusts,” making it easier for multiple people to own silencers. One large retailer, Silencer Central, offers financing for customers, mails out fingerprinting kits, and ships silencers to approved customers’ doors so they never have to set foot in a brick-and-mortar store. Another large retailer, the Silencer Shop, has placed kiosks in gun shops across the U.S. to collect personal information and fingerprints.
Perhaps most significant is the fact that the ATF debuted a new online “eForms” system in December 2021 — after successful lobbying from the NSSF — that has led to much faster NFA approvals. What used to take several months has been reduced to a matter of days. Silencer Central and the Silencer Shop have claimed that their customers have been approved to own silencers in as little as three to seven days, respectively.
These efforts have paid off for the gun industry. ATF data shows that Americans purchased and registered over 830,000 new silencers between May 2021 and January 2024, bringing the total number of registered silencers to 3.5 million.1This total includes civilian silencers as well as those owned by state and local law enforcement. The National Firearm Registration and Transfer Record (NFRTR) does not include those owned by the U.S. government: https://www.atf.gov/firearms/docs/undefined/atf-national-firearms-act-handbook-chapter-3/download. This 31-percent increase occurred in just 32 months — compared to the 87 years it took for Americans to stockpile 2.7 million silencers between 1934 and 2021.2ATF, “Firearms Commerce in the United States: Annual Statistical Update 2021,” 16, https://www.atf.gov/firearms/docs/report/2021-firearms-commerce-report/download.
The table below shows the number of silencers owned in each state as of January 2024 and compares those figures to the ATF’s previous data.
| State | Registered Silencers (through January 2024) | Prior Figures (to May 2021) | Difference | % Change |
|---|---|---|---|---|
| TOTAL | 3,493,765 | 2,663,730 | 830,035 | 31.2% |
| Alabama | 79,936 | 64,506 | 15,430 | 23.9% |
| Alaska | 20,367 | 15,192 | 5,175 | 34.1% |
| Arkansas | 47,864 | 38,058 | 9,806 | 25.8% |
| Arizona | 112,837 | 85,353 | 27,484 | 32.2% |
| California | 18,996 | 17,271 | 1,725 | 10.0% |
| Colorado | 99,595 | 67,008 | 32,587 | 48.6% |
| Connecticut | 25,227 | 18,648 | 6,579 | 35.3% |
| Delaware | 1,154 | 411 | 743 | 180.8% |
| Florida | 242,267 | 175,156 | 67,111 | 38.3% |
| Georgia | 176,931 | 129,566 | 47,365 | 36.6% |
| Hawaii | 461 | 403 | 58 | 14.4% |
| Iowa | 35,061 | 22,529 | 12,532 | 55.6% |
| Idaho | 56,960 | 40,755 | 16,205 | 39.8% |
| Illinois | 3,930 | 3,297 | 633 | 19.2% |
| Indiana | 85,960 | 63,249 | 22,711 | 35.9% |
| Kansas | 41,606 | 31,811 | 9,795 | 30.8% |
| Kentucky | 61,078 | 44,040 | 17,038 | 38.7% |
| Louisiana | 67,831 | 72,042 | -4,211 | -5.8% |
| Massachussetts | 13,984 | 10,409 | 3,575 | 34.3% |
| Maryland | 43,851 | 32,275 | 11,576 | 35.9% |
| Maine | 14,066 | 8,285 | 5,781 | 69.8% |
| Michigan | 73,976 | 49,324 | 24,652 | 50.0% |
| Minnesota | 50,832 | 48,154 | 2,678 | 5.6% |
| Missouri | 65,859 | 49,754 | 16,105 | 32.4% |
| Mississippi | 44,911 | 36,545 | 8,366 | 22.9% |
| Montana | 40,706 | 25,409 | 15,297 | 60.2% |
| North Carolina | 110,142 | 76,759 | 33,383 | 43.5% |
| North Dakota | 29,459 | 23,042 | 6,417 | 27.8% |
| Nebraska | 34,195 | 25,879 | 8,316 | 32.1% |
| New Hampshire | 43,382 | 36,954 | 6,428 | 17.4% |
| New Jersey | 6,362 | 3,889 | 2,473 | 63.6% |
| New Mexico | 28,537 | 19,873 | 8,664 | 43.6% |
| Nevada | 50,048 | 37,880 | 12,168 | 32.1% |
| New York | 9,354 | 7,406 | 1,948 | 26.3% |
| Ohio | 92,150 | 68,736 | 23,414 | 34.1% |
| Oklahoma | 72,167 | 62,404 | 9,763 | 15.6% |
| Oregon | 72,580 | 49,197 | 23,383 | 47.5% |
| Pennsylvania | 116,607 | 83,563 | 33,044 | 39.5% |
| Rhode Island | 100 | 96 | 4 | 4.2% |
| South Carolina | 60,465 | 50,422 | 10,043 | 19.9% |
| South Dakota | 109,738 | 55,666 | 54,072 | 97.1% |
| Tennessee | 91,539 | 60,573 | 30,966 | 51.1% |
| Texas | 591,349 | 529,150 | 62,199 | 11.8% |
| Utah | 113,560 | 79,557 | 34,003 | 42.7% |
| Virginia | 113,046 | 90,454 | 22,592 | 25.0% |
| Vermont | 5,270 | 3,528 | 1,742 | 49.4% |
| Washington | 110,735 | 78,279 | 32,456 | 41.5% |
| Wisconsin | 62,684 | 40,596 | 22,088 | 54.4% |
| West Virginia | 20,225 | 13,696 | 6,529 | 47.7% |
| Wyoming | 23,825 | 16,681 | 7,144 | 42.8% |
To meet this demand, more companies are producing silencers today than ever before. Dozens of companies primarily focus on manufacturing silencers, but a number of gun makers have added silencers to their catalogs in recent years — in addition to firearms with threaded barrels to accept silencers. Sig Sauer and Ruger introduced their first silencers in 2013 and 2016, respectively, and Smith & Wesson purchased Gemtech, a large silencer manufacturer, in 2017. More examples can be found here.
diy silencer-building kits
A number of online retailers have also offered “solvent traps” and “fuel filters” that are essentially unfinished, and untraceable, firearm silencers — much like the 80-percent frames and receivers used to build “ghost guns.” The products have similar features as silencers, including outer metal tubes, gas expansion chambers (or “baffles”) to help muffle the sound of gunfire, and even threading so they can be attached to barrels. The only thing required to transform one of these devices into a functional silencer is to drill out an end cap, allowing a bullet to pass through.
Retailers and proponents of these devices claim that solvent traps are merely cleaning accessories that, once attached to the muzzle of a firearm, will catch solvents that drip from the barrel as it is cleaned. Not only is this unnecessary — people have been cleaning firearms for decades without “solvent traps” by using an appropriate amount of cleaning solvent — but it does not explain why many of these devices feature sound-dampening baffles.
Along with marketing these items as cleaning accessories, some “solvent trap” retailers stated in the past that customers must receive ATF approval before drilling out the end cap and creating a complete silencer, strongly suggesting that the sellers know what customers can do with the products. But there is no mechanism to prevent someone, including criminals, from completing the silencer without receiving ATF approval.
The ATF’s RESPONSE TO DIY SILENCER KITS
“Solvent traps” and other DIY silencer kits are an obvious attempt to circumvent federal regulations, which define silencers as “any device for silencing, muffling, or diminishing the report of a portable firearm, including any combination of parts, designed or redesigned, and intended for the use in assembling or fabricating a firearm silencer or firearm muffler, and any part intended only for use in such assembly or fabrication” (emphasis added).
Since 2017, the ATF has shut down several manufacturers and retailers for selling unregistered NFA items, including Darkside Defense, Diversified Machine, SD Tactical Arms, and Solvent Traps Etc., recognizing that those retailers’ “solvent traps” were indeed silencers. But some “solvent trap” and “fuel filter” retailers appear to still be operating online.
Between 2017 and 2021, law enforcement personnel recovered an estimated 9,130 privately made silencers and silencer parts, representing a 176.8-percent increase from the 3,298 recovered between 2012 and 2016, and several arrests have been made, including a Proud Boy supporter and January 6 rioter who was convicted of unlawful possession of unregistered silencers after purchasing three “solvent traps.”
The ATF has also denied NFA applications from people who have purchased “solvent traps” and attempted to register them as silencers retroactively. When the agency denied 850 such applications in early 2022, the agency stated that “it is unlawful for a person to make a silencer from a device or part that falls under the federal definition of silencer and was transferred to the applicant without complying with the tax, transfer, and registration requirements of the NFA.”
In November 2023, the ATF issued an open letter reiterating that some “solvent traps” are considered silencers, regardless of how they’re marketed, “because they have the objective design features and characteristics indicating that the device is ‘for’ reducing the report of a portable firearm,” including sound-dampening baffles.
According to the ATF, “Over the years, many companies involved in marketing such ‘solvent traps’ have asserted that they are permitted to manufacture, transfer, or import these items because they are not yet ‘complete’ and therefore do not qualify as ‘firearm silencers’ under Federal law. However, this assertion is incorrect because a component of a ‘firearm silencer’ need not be fully functional before it is recognized as a ‘part intended only for use’ in assembling or fabricating a ‘firearm silencer.’”
Finally, the letter makes it clear that individuals cannot purchase one of these kits and then attempt to register the silencer with the ATF. “An NFA firearm that has already been made/manufactured in violation of the NFA may not be registered by the current possessor.”