103RD GENERAL ASSEMBLY
State of Illinois
2023 and 2024
HB4550

Introduced , by Rep. Margaret Croke

SYNOPSIS AS INTRODUCED:
720 ILCS 5/24-5.1

Amends the Criminal Code of 2012. Increases from a Class A misdemeanor to a Class 4 felony the penalty for a first violation of the provisions that prohibit the knowing possession, transportation, purchase, or receipt of an unfinished frame or receiver of a firearm unless: (1) the party possessing or receiving the unfinished frame or receiver is a federal firearms importer or federal firearms manufacturer; (2) the unfinished frame or receiver is possessed or transported by a person for transfer to a federal firearms importer or federal firearms manufacturer; or (3) the unfinished frame or receiver has been imprinted with a serial number issued by a federal firearms importer or federal firearms manufacturer.
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A BILL FOR

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1 AN ACT concerning criminal law.
2 Be it enacted by the People of the State of Illinois,
3represented in the General Assembly:
4 Section 5. The Criminal Code of 2012 is amended by
5changing Section 24-5.1 as follows:
6 (720 ILCS 5/24-5.1)
7 Sec. 24-5.1. Serialization of unfinished frames or
8receivers; prohibition on unserialized firearms; exceptions;
9penalties.
10 (a) In this Section:
11 "Bona fide supplier" means an established business entity
12engaged in the development and sale of firearms parts to one or
13more federal firearms manufacturers or federal firearms
14importers.
15 "Federal firearms dealer" means a licensed manufacturer
16pursuant to 18 U.S.C. 921(a)(11).
17 "Federal firearms importer" means a licensed importer
18pursuant to 18 U.S.C. 921(a)(9).
19 "Federal firearms manufacturer" means a licensed
20manufacturer pursuant to 18 U.S.C. 921(a)(10).
21 "Frame or receiver" means a part of a firearm that, when
22the complete weapon is assembled, is visible from the exterior
23and provides housing or a structure designed to hold or

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1integrate one or more fire control components, even if pins or
2other attachments are required to connect those components to
3the housing or structure. For models of firearms in which
4multiple parts provide such housing or structure, the part or
5parts that the Director of the federal Bureau of Alcohol,
6Tobacco, Firearms and Explosives has determined are a frame or
7receiver constitute the frame or receiver. For purposes of
8this definition, "fire control component" means a component
9necessary for the firearm to initiate, complete, or continue
10the firing sequence, including any of the following: hammer,
11bolt, bolt carrier, breechblock, cylinder, trigger mechanism,
12firing pin, striker, or slide rails.
13 "Security exemplar" means an object to be fabricated at
14the direction of the United States Attorney General that is
15(1) constructed of 3.7 ounces of material type 17-4 PH
16stainless steel in a shape resembling a handgun and (2)
17suitable for testing and calibrating metal detectors.
18 "Three-dimensional printer" means a computer or
19computer-drive machine capable of producing a
20three-dimensional object from a digital model.
21 "Undetectable firearm" means (1) a firearm constructed
22entirely of non-metal substances; (2) a firearm that, after
23removal of all parts but the major components of the firearm,
24is not detectable by walk-through metal detectors calibrated
25and operated to detect the security exemplar; or (3) a firearm
26that includes a major component of a firearm, which, if

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1subject to the types of detection devices commonly used at
2airports for security screening, would not generate an image
3that accurately depicts the shape of the component.
4"Undetectable firearm" does not include a firearm subject to
5the provisions of 18 U.S.C. 922(p)(3) through (6).
6 "Unfinished frame or receiver" means any forging, casting,
7printing, extrusion, machined body, or similar article that:
8 (1) has reached a stage in manufacture where it may
9 readily be completed, assembled, or converted to be a
10 functional firearm; or
11 (2) is marketed or sold to the public to become or be
12 used as the frame or receiver of a functional firearm once
13 completed, assembled, or converted.
14 "Unserialized" means lacking a serial number imprinted by:
15 (1) a federal firearms manufacturer, federal firearms
16 importer, federal firearms dealer, or other federal
17 licensee authorized to provide marking services, pursuant
18 to a requirement under federal law; or
19 (2) a federal firearms dealer or other federal
20 licensee authorized to provide marking services pursuant
21 to subsection (f) of this Section.
22 (b) It is unlawful for any person to knowingly sell, offer
23to sell, or transfer an unserialized unfinished frame or
24receiver or unserialized firearm, including those produced
25using a three-dimensional printer, unless the party purchasing
26or receiving the unfinished frame or receiver or unserialized

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1firearm is a federal firearms importer, federal firearms
2manufacturer, or federal firearms dealer.
3 (c) Beginning 180 days after the effective date of this
4amendatory Act of the 102nd General Assembly, it is unlawful
5for any person to knowingly possess, transport, or receive an
6unfinished frame or receiver, unless:
7 (1) the party possessing or receiving the unfinished
8 frame or receiver is a federal firearms importer or
9 federal firearms manufacturer;
10 (2) the unfinished frame or receiver is possessed or
11 transported by a person for transfer to a federal firearms
12 importer or federal firearms manufacturer; or
13 (3) the unfinished frame or receiver has been
14 imprinted with a serial number issued by a federal
15 firearms importer or federal firearms manufacturer in
16 compliance with subsection (f) of this Section.
17 (d) Beginning 180 days after the effective date of this
18amendatory Act of the 102nd General Assembly, unless the party
19receiving the firearm is a federal firearms importer or
20federal firearms manufacturer, it is unlawful for any person
21to knowingly possess, purchase, transport, or receive a
22firearm that is not imprinted with a serial number by (1) a
23federal firearms importer or federal firearms manufacturer in
24compliance with all federal laws and regulations regulating
25the manufacture and import of firearms or (2) a federal
26firearms manufacturer, federal firearms dealer, or other

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1federal licensee authorized to provide marking services in
2compliance with the unserialized firearm serialization process
3under subsection (f) of this Section.
4 (e) Any firearm or unfinished frame or receiver
5manufactured using a three-dimensional printer must also be
6serialized in accordance with the requirements of subsection
7(f) within 30 days after the effective date of this amendatory
8Act of the 102nd General Assembly, or prior to reaching a stage
9of manufacture where it may be readily completed, assembled,
10or converted to be a functional firearm.
11 (f) Unserialized unfinished frames or receivers and
12unserialized firearms serialized pursuant to this Section
13shall be serialized in compliance with all of the following:
14 (1) An unserialized unfinished frame or receiver and
15 unserialized firearm shall be serialized by a federally
16 licensed firearms dealer or other federal licensee
17 authorized to provide marking services with the licensee's
18 abbreviated federal firearms license number as a prefix
19 (which is the first 3 and last 5 digits) followed by a
20 hyphen, and then followed by a number as a suffix, such as
21 12345678-(number). The serial number or numbers must be
22 placed in a manner that accords with the requirements
23 under federal law for affixing serial numbers to firearms,
24 including the requirements that the serial number or
25 numbers be at the minimum size and depth, and not
26 susceptible to being readily obliterated, altered, or

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1 removed, and the licensee must retain records that accord
2 with the requirements under federal law in the case of the
3 sale of a firearm. The imprinting of any serial number
4 upon a undetectable firearm must be done on a steel plaque
5 in compliance with 18 U.S.C. 922(p).
6 (2) Every federally licensed firearms dealer or other
7 federal licensee that engraves, casts, stamps, or
8 otherwise conspicuously and permanently places a unique
9 serial number pursuant to this Section shall maintain a
10 record of such indefinitely. Licensees subject to the
11 Firearm Dealer License Certification Act shall make all
12 records accessible for inspection upon the request of the
13 Illinois State Police or a law enforcement agency in
14 accordance with Section 5-35 of the Firearm Dealer License
15 Certification Act.
16 (3) Every federally licensed firearms dealer or other
17 federal licensee that engraves, casts, stamps, or
18 otherwise conspicuously and permanently places a unique
19 serial number pursuant to this Section shall record it at
20 the time of every transaction involving the transfer of a
21 firearm, rifle, shotgun, finished frame or receiver, or
22 unfinished frame or receiver that has been so marked in
23 compliance with the federal guidelines set forth in 27 CFR
24 478.124.
25 (4) Every federally licensed firearms dealer or other
26 federal licensee that engraves, casts, stamps, or

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1 otherwise conspicuously and permanently places a unique
2 serial number pursuant to this Section shall review and
3 confirm the validity of the owner's Firearm Owner's
4 Identification Card issued under the Firearm Owners
5 Identification Card Act prior to returning the firearm to
6 the owner.
7 (g) Within 30 days after the effective date of this
8amendatory Act of the 102nd General Assembly, the Director of
9the Illinois State Police shall issue a public notice
10regarding the provisions of this Section. The notice shall
11include posting on the Illinois State Police website and may
12include written notification or any other means of
13communication statewide to all Illinois-based federal firearms
14manufacturers, federal firearms dealers, or other federal
15licensees authorized to provide marking services in compliance
16with the serialization process in subsection (f) in order to
17educate the public.
18 (h) Exceptions. This Section does not apply to an
19unserialized unfinished frame or receiver or an unserialized
20firearm that:
21 (1) has been rendered permanently inoperable;
22 (2) is an antique firearm, as defined in 18 U.S.C.
23 921(a)(16);
24 (3) was manufactured prior to October 22, 1968;
25 (4) is an unfinished frame or receiver and is
26 possessed by a bona fide supplier exclusively for transfer

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