SPRINGFIELD — Illinoisans who want to purchase a gun will soon have to wait 72 hours to purchase the weapon.Gov. Bruce Rauner signed Senate Bill 3256, which creates a 72-hour waiting period for purchasing all guns. Currently, someone must wait 24 hours to obtain an assault weapon and 72 hours to obtain a handgun, but the new 72-hour waiting period will apply to all guns.The 72 hours is considered a “cooling-off …