Amends the Criminal Code of 2012. Makes it unlawful to deliver, sell, or purchase or cause to be delivered, sold, or purchased or cause to be possessed by another, an assault weapon, assault weapon attachment, .50 caliber rifle, or .50 caliber cartridge. Makes it unlawful for any person to knowingly possess an assault weapon, .50 caliber rifle, or .50 caliber cartridge 300 days after the effective date of this amendatory Act, except possession of weapons registered with the State Police in the time provided. Provides exemptions and penalties. Prohibits delivery, sale, purchase, or possession of large capacity ammunition feeding devices. Provides exemptions and penalties. Prohibits the knowing sale, manufacture, purchase, possession, or carrying of a trigger modification device. Defines "trigger modification device". Effective immediately.