Hi Omar, no sir, due to the pistol grip. (the muzzle brake is not prohibited)
Prohibited - A semiautomatic rifle that has the capacity to accept a detachable magazine or that may be
readilymodified to accept a detachable magazine, if the firearm has one or more of the following:
❌ i. a pistol grip or thumbhole stock;
ii. any feature capable of functioning as a protruding grip that can be held by the non-trigger hand;
iii. a folding, telescoping, thumbhole, or detachable stock, or a stock that is otherwise foldable or adjustable in a manner that operates to reduce the length, size, or any other dimension, or otherwise enhances the concealability of, the weapon;
iv. a flash suppressor;
v. a grenede launcher;
vi. a shroud attached to the barrel or that partially or completely encircles the barrel, allowing the bearer to hold the firearm with the non-trigger hand without being burned, but excluding a slide that encloses the barrel.
budsgunshop.com/feeds/state_reg/illinois_restrictions.pdf

The legality of the GLFA GL10 .300 Win Mag Semi Auto Rifle in Illinois can be complex due to the state’s strict firearm regulations. Generally, semi-automatic rifles are subject to various restrictions in Illinois, especially in certain areas like Cook County and the city of Chicago.
To ensure compliance, it’s best to check with local law enforcement or a legal expert in Illinois. Additionally, firearms must be transferred through a Federal Firearms License (FFL) holder.

Sorry but Not one bit Legal in Illinois. Explanations already given.

Hi Omar and welcome. No Sir, due to the detachable magazine and Pistol Grip and Muzzle Device. Details under Rifles here: budsgunshop.com/feeds/state_reg/illinois_restrictions.pdf