(A) A person commits the offense of unlawful possession of firearms or firearm ammunition when:
(1) He or she is under 18 years of age and has in his or her possession any firearm of a size which may be concealed upon the person;
(2) He or she is under 21 years of age, has been convicted of a misdemeanor other than a traffic offense or adjudged delinquent and has any firearms or firearm ammunition in his or her possession;
(3) He or she is a narcotic addict and has any firearms or firearm ammunition in his or her possession;
(4) He or she has been a patient in a mental institution within the past five years and has any firearms or firearm ammunition in his or her possession. For purposes of this division (A)(4):
(a) MENTAL INSTITUTION means any hospital, institution, clinic, evaluation facility, mental health center, or part thereof, which is used primarily for the care or treatment of persons with mental illness; and
(b) PATIENT IN A MENTAL INSTITUTION means the person was admitted, either voluntarily or involuntarily, to a mental institution for mental health treatment, unless the treatment was voluntary and solely for an alcohol abuse disorder and no other secondary substance abuse disorder or mental illness.
(5) He or she is a person with an intellectual disability and has any firearms or firearm ammunition in his or her possession; or
(6) He or she has in his or her possession any explosive bullet. For the purposes of this division (A)(6):
(a) EXPLOSIVE BULLET means the projectile portion of an ammunition cartridge which contains or carries an explosive charge which will explode upon contact with the flesh of a human or an animal; and
(b) CARTRIDGE means a tubular metal case having a projectile affixed at the front thereof and a cap or primer at the rear end thereof, with the propellent contained in the tube between the projectile and the cap.
(B) Nothing in division (A)(1) above prohibits a person under 18 years of age from participating in any lawful recreational activity with a firearm such as, but not limited to, practice shooting at targets upon established public or private target ranges or hunting, trapping, or fishing in accordance with the Wildlife Code (see 520 ILCS 5) or the Fish and Aquatic Life Code (see 515 ILCS 5).
(720 ILCS 5/24-3.1)
Penalty, see § 137.99