silencer
Under federal firearms law, a “silencer” or a “firearm muffler” is defined under 18 U.S.C. § 921(a)(25) as “any device for silencing, muffling, or diminishing the report of a portable firearm.” The definition expressly includes “any combination of parts, designed or redesigned, and intended for use in assembling or fabricating a firearm silencer or firearm muffler,” as well as “any part intended only for use in such assembly or fabrication.” Courts have held that a device need not actually function as a silencer to fall within the statutory definition. Instead, the definition focuses on the device's intended purpose and design. For example, in United States v. Rose, 522 F.3d 710 (2008), the Sixth Circuit held that the statutory definition focuses on the intended application of a silencer rather than its actual demonstrated operation. Thus, the government need not establish that a device was actually capable of silencing a firearm when the evidence establishes that the device was intended to function as a silencer.
The National Firearms Act (NFA) classifies a silencer as a “firearm” for purposes of the NFA. Specifically, 26 U.S.C. § 5845(a)(7) includes “any silencer (as defined in section 921 of title 18, United States Code)” within the NFA's definition of “firearm.” Congress amended § 5845(a)(7) in 1986 to incorporate the definition in 18 U.S.C. § 921(a)(25), which means that the definitions of “firearm silencer” and “firearm muffler” found in § 921(a)(25) also govern the NFA's treatment of silencers.
[Last reviewed in August of 2026 by the Wex Definitions Team]
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