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H.R. 4221
U.S. House•In House Committee
Summary
H.R. 4221, the Undetectable Firearms Modernization Act, was introduced in the House on Jun 27, 2025 by Rep. Madeleine Dean (D). It was referred to Judiciary, and last saw action on Jun 27, 2025: Referred to the House Committee on the Judiciary.
Record
Text
H.R. 4221 has no co-sponsors and has not gone to a roll call.
hb4221/introduced-in-house.txt119 HR 4221 IH: Undetectable Firearms Modernization ActU.S. House of Representatives2025-06-27text/xmlENPursuant to Title 17 Section 105 of the United States Code, this file is not subject to copyright protection and is in the public domain.I 119th CONGRESS 1st Session H. R. 4221 IN THE HOUSE OF REPRESENTATIVES June 27, 2025 Ms. Dean of Pennsylvania introduced the following bill; which was referred to the Committee on the Judiciary A BILLTo modernize the Undetectable Firearms Act of 1988.1.Short titleThis Act may be cited as the Undetectable Firearms Modernization Act .2.Modernization of the prohibition on undetectable firearmsSection 922(p) of title 18, United States Code, is amended—(1)in paragraph (1)—(A)in subparagraph (A), by striking grips, stocks, and magazines, is not as detectable as the Security Exemplar, by walk-through metal detectors calibrated and operated to detect the Security Exemplar and inserting all parts other than major components, does not contain detectable material ; and(B)in subparagraph (B), by striking when subjected to inspection by the types of x-ray machines commonly used at airports, does not generate and inserting the following: if subjected to inspection by the types of detection devices commonly used at airports for security screening, would not generate ;(2)in paragraph (2)—(A)by striking subparagraph (B) and inserting the following:(B)the term major component , with respect to a firearm—(i)means the slide or cylinder, or the frame or receiver of the firearm; and(ii)in the case of a rifle or shotgun, includes the barrel of the firearm; and; and(B)by striking subparagraph (C) and the proviso that follows and inserting the following:(C)the term detectable material means material that produces a magnetic field that is equivalent in strength to the magnetic field produced by 3.7 ounces of 17–4 PH stainless steel.;(3)in paragraph (3)—(A)in the first sentence, by inserting after of a firearm the following: , including a prototype, ; and(B)by striking the second sentence; and(4)in paragraph (5), by striking shall not apply to any firearm which and all that follows and inserting the following:shall not apply to—(A)any firearm received by, in the possession of, or under the control of the United States; or(B)the manufacture, importation, possession, transfer, receipt, shipment, or delivery of a firearm by a licensed manufacturer or licensed importer pursuant to an existing contract with the United States..
Tracker
The tracker indicates the progress of this legislation as it moves through the legislative process.
- Introduced2025-06-27
- Passed House
- Passed Senate
- Conference
- To President
- Became Law
CRS Summary
The summaries are the Congressional Research Service’s, one per stage. Read them in full.
Introduced in House Jun 27, 2025
hb4221/introduced-in-house.mdShown Here:
Introduced in House (06/27/2025)
Undetectable Firearms Modernization Act
This bill strengthens the detectability standard for firearms under federal firearms laws.
Current law requires firearms to be detectable by walk-through metal detectors after the removal of grips, stocks, and magazines. Specifically, firearms must be as detectable as a security exemplar (i.e., a piece of stainless steel that is 3.7 ounces and in a shape resembling a handgun). There are exceptions, including for firearms manufactured for or sold to U.S. military or intelligence agencies.
This bill requires firearms to contain detectable material after the removal of all parts other than major components. It defines detectable material as material that produces a magnetic field equivalent to that produced by 3.7 ounces of stainless steel. The bill also revises and broadens the exceptions to include firearms (1) received by, in the possession of, or under the control of the United States; or (2) produced pursuant to a contract with the United States.
Sponsors
Rep. Madeleine Dean (D) sponsors H.R. 4221 alone.
Committees
H.R. 4221 went before 1 committee: Judiciary.
Actions
H.R. 4221 has taken 2 actions since Jun 27, 2025.
| Chamber | Action | |||
|---|---|---|---|---|
Jun 27, 2025 | House | Introduced in House | ||
Jun 27, 2025 | House | Referred to the House Committee on the Judiciary.Judiciary Committee |
Votes
H.R. 4221 has not gone to a roll call.
Titles
H.R. 4221 goes by 3 titles, 1 of them short titles.
- Undetectable Firearms Modernization Act — Display Title
- Undetectable Firearms Modernization Act — Short Title(s) as Introduced
- To modernize the Undetectable Firearms Act of 1988. — Official Title as Introduced
Lobbying
1 client hired 1 firm and 3 registered lobbyists who named H.R. 4221 in 5 quarterly filings, 2025 to 2026. Reported under the Lobbying Disclosure Act; a filing’s income covers everything its registrant worked that quarter, so the amounts below are the filings’, not this bill’s.
Filed under Firearms/Guns/Ammunition.
Clients
Who paid to be heard, by how many filings named the bill.
| Client | Business | State | Firms | Filings | Reported |
|---|---|---|---|---|---|
| NATIONAL ASSOCIATION FOR GUN RIGHTS | — | Colorado | 1 | 5 | — |
Firms
Registrants who filed on the bill, by filings.
| Registrant | Clients | Filings | Reported |
|---|---|---|---|
| NATIONAL ASSOCIATION FOR GUN RIGHTS | 1 | 5 | — |
Lobbyists
Named on the filings that cite the bill.
| Lobbyist | Firms | Clients | Filings |
|---|---|---|---|
| ANGELO VELTRI | 1 | 1 | 5 |
| DUDLEY BROWN | 1 | 1 | 5 |
| DUSTIN CURTIS | 1 | 1 | 5 |
Filings
The documents themselves, on the Senate’s Lobbying Disclosure site, largest reported first.
| Client | Registrant | Period | Reported | Document |
|---|---|---|---|---|
| NATIONAL ASSOCIATION FOR GUN RIGHTS | NATIONAL ASSOCIATION FOR GUN RIGHTS | 2025 second_quarter | $304.8K | 2nd Quarter - Report |
| NATIONAL ASSOCIATION FOR GUN RIGHTS | NATIONAL ASSOCIATION FOR GUN RIGHTS | 2025 third_quarter | $296.6K | 3rd Quarter - Report |
| NATIONAL ASSOCIATION FOR GUN RIGHTS | NATIONAL ASSOCIATION FOR GUN RIGHTS | 2026 second_quarter | $293.3K | 2nd Quarter - Report |
| NATIONAL ASSOCIATION FOR GUN RIGHTS | NATIONAL ASSOCIATION FOR GUN RIGHTS | 2026 first_quarter | $289.9K | 1st Quarter - Report |
| NATIONAL ASSOCIATION FOR GUN RIGHTS | NATIONAL ASSOCIATION FOR GUN RIGHTS | 2025 fourth_quarter | $136.3K | 4th Quarter - Report |
Classification
The Congressional Research Service files H.R. 4221 under Crime and Law Enforcement, one of its 31 policy areas.
CRS Subjects
CRS assigns every bill one policy area from its 31; H.R. 4221’s is Crime and Law Enforcement.
hr4221/policy-areas.txtConstitutional authority
The clause the sponsor cites as Congress’s power to enact H.R. 4221, as entered in the Congressional Record.
[Congressional Record Volume 171, Number 111 (Friday, June 27, 2025)][House]From the Congressional Record Online through the Government Publishing Office [www.gpo.gov]By Ms. DEAN of Pennsylvania:H.R. 4221.Congress has the power to enact this legislation pursuantto the following:Article 1, Section 8[Page H3033]
Source: congress.gov · legiscan.com