Synopsis As Introduced Amends the Criminal Code of 2012 concerning unlawful use of weapons. Provides that 120 days after the effective date of the bill, it is unlawful for a person to knowingly import, sell, manufacture, transfer, or possess, in this State, a bump-fire stock for a semi-automatic firearm that does not convert the semi-automatic firearm into a machine gun. Defines "bump-fire stock" as a butt stock designed to be attached to a semi-automatic firearm and designed, made, or altered, and intended to increase the rate of fire achievable with the firearm to that of a fully automatic firearm by using the energy from the recoil of the firearm to generate reciprocating action that facilitates repeated activation of the trigger. Provides that a violation is a Class 4 felony. Effective immediately.