SPRINGFIELD – Illinoisans who own weapons that can no longer be purchased or sold in the state under its new assault weapons ban will soon be able to register those weapons so they can legally keep them.The law, officially known as the Protect Illinois Communities Act, bans the sale and possession of firearms defined as “assault weapons” as well as assault weapon attachments, .50 caliber rifles, .50 caliber cartridges and high-capacity magazines.However, the law provides an exception for Illinoisans who …