Wisconsin SB 332: Relating to: prohibition against undetectable firearms, possessing a frame or receiver of a firearm without a serial number, and providing a penalty.

Bill Text

2025 - 2026 LEGISLATURE LRB-3489/1
CMH:klm
2025 SENATE BILL 332
June 19, 2025 - Introduced by Senators HESSELBEIN, L. JOHNSON, LARSON, ROYS,
DASSLER-ALFHEIM, DRAKE, HABUSH SINYKIN, KEYESKI, RATCLIFF, SMITH,
SPREITZER and CARPENTER, cosponsored by Representatives JOERS,
FITZGERALD, SUBECK, HONG, ANDRACA, STUBBS, VINING, CLANCY, ARNEY,
BARE, BROWN, CRUZ, DESMIDT, EMERSON, GOODWIN, HYSELL, HAYWOOD,
JOHNSON, KIRSCH, MAYADEV, MIRESSE, MOORE OMOKUNDE, NEUBAUER,
PALMERI, PRADO, RIVERA-WAGNER, ROE, SHEEHAN, SINICKI, SNODGRASS,
STROUD, TAYLOR, TENORIO and UDELL. Referred to Committee on Licensing,
Regulatory Reform, State and Federal Affairs.
AN ACT to amend 939.6195 (1) (a) 1. and 941.291 (1) (b); to create 941.293 of
the statutes; relating to: prohibition against undetectable firearms,
possessing a frame or receiver of a firearm without a serial number, and
providing a penalty.
Analysis by the Legislative Reference Bureau
This bill prohibits the manufacture, transportation, sale, possession, and
carrying of firearms that cannot be detected by metal detectors or airport x-ray
machines or scanners. Federal law currently has a comparable prohibition; under
this bill, the person would violate state law as well. A person who violates the state
prohibition is guilty of a Class G felony.
This bill also prohibits the sale, posting, provision, or possession of plans for
manufacturing an undetectable firearm. A person who violates this prohibition is
guilty of a Class H felony.
Finally, the bill prohibits the possession of a frame or a receiver of a firearm
that is not marked with a serial number. A person who violates this prohibition is
guilty of a Class I felony.
Because this bill creates a new crime or revises a penalty for an existing crime,
1
2
3
4

2025 - 2026 Legislature
SENATE BILL 332
- 2 - LRB-3489/1
CMH:klm
SECTION 1
the Joint Review Committee on Criminal Penalties may be requested to prepare a
report.
The people of the state of Wisconsin, represented in senate and assembly, do
enact as follows:
SECTION 1. 939.6195 (1) (a) 1. of the statutes is amended to read:
939.6195 (1) (a) 1. A violation of s. 941.29 or, 941.2905, or 941.293.
SECTION 2. 941.291 (1) (b) of the statutes is amended to read:
941.291 (1) (b) “Violent felony” means any felony, or the solicitation,
conspiracy, or attempt to commit any felony, under s. 943.23 (1m) or (1r), 1999
stats., or s. 943.23 (1g), 2021 stats., or s. 940.01, 940.02, 940.03, 940.05, 940.06,
940.08, 940.09, 940.10, 940.19, 940.195, 940.198, 940.20, 940.201, 940.203,
940.204, 940.21, 940.225, 940.23, 940.285 (2), 940.29, 940.295 (3), 940.30, 940.305,
940.31, 940.43 (1) to (3), 940.45 (1) to (3), 941.20, 941.26, 941.28, 941.29, 941.293,
941.30, 941.327, 943.01 (2) (c), 943.011, 943.013, 943.02, 943.04, 943.06, 943.10 (2),
943.231 (1), 943.32, 943.81, 943.82, 943.83, 943.85, 943.86, 943.87, 943.88, 943.89,
943.90, 946.43, 947.015, 948.02 (1) or (2), 948.025, 948.03, 948.04, 948.05, 948.06,
948.07, 948.08, 948.085, or 948.30; or, if the victim is a financial institution, as
defined in s. 943.80 (2), a felony, or the solicitation, conspiracy, or attempt to commit
a felony under s. 943.84 (1) or (2).
SECTION 3. 941.293 of the statutes is created to read:
941.293 Undetectable firearms; serial numbers on firearm
components. (1) In this section:
(a) “Major component” means the barrel, the slide or cylinder, or the frame or
receiver of a firearm.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

2025 - 2026 Legislature
SENATE BILL 332
- 3 - LRB-3489/1
CMH:klm
SECTION 3
(b) “Undetectable firearm” means any of the following:
1. A firearm that, after the removal of grips, stocks, and magazines, is not
detectable by a metal detector calibrated to detect a security exemplar, as defined in
18 USC 922 (p) (2) (C).
2. A firearm if any major component of it does not generate an image that
accurately depicts the shape of the component when subject to inspection by
security scanners, x-ray machines, or other security devices commonly used at
airports.
(2) (a) 1. Whoever sells, offers to sell, transfers, transports, manufactures,
possesses, or goes armed with an undetectable firearm is guilty of a Class G felony.
2. Whoever sells, offers to sell, transfers, posts, provides to another, or
possesses plans for manufacturing an undetectable firearm is guilty of a Class H
felony.
(b) Paragraph (a) does not apply to a person who is licensed by a state or the
federal government to manufacture undetectable firearms while the person is on
official duty. Paragraph (a) 1. does not apply to a law enforcement officer while on
official duty or to armed forces or national guard personnel while on official duty.
(3) (a) Whoever possesses a frame or a receiver of a firearm that is not
attached to a firearm and that is not marked or engraved with a serial number is
guilty of a Class I felony.
(b) Paragraph (a) does not apply to a firearm frame or receiver manufactured
before 1968, a person who is licensed by a stat