No SBR in Illinois despite federal license, unless you want to spend time in the pen:
720 ILCS 5/24-1 (720 ILCS 5/Art. 24 heading)
ARTICLE 24. DEADLY WEAPONS
(720 ILCS 5/24‑1) (from Ch. 38, par. 24‑1)
Sec. 24‑1. Unlawful Use of Weapons.
(a) A person commits the offense of unlawful use of weapons when he knowingly:
[SNIP SNIP]
(6) Possesses any device or attachment of any kind
designed, used or intended for use in
silencing the report of any firearm; or
(7) Sells, manufactures, purchases, possesses or
carries:
(i) a machine gun, [SNIP]
(ii)
any rifle having one or more barrels less
than 16 inches in length or a shotgun having one or more barrels less than 18 inches in length or any weapon made from a rifle or shotgun, whether by alteration, modification, or otherwise, if such a weapon as modified has an overall length of less than 26 inches; or [SNIP]
(b) Sentence. [SNIP] a person convicted of a violation of subsection 24‑1(a)(6) or 24‑1(a)(7)(ii) or (iii) commits a Class 3 felony. A person convicted of a violation of subsection 24‑1(a)(7)(i) commits a Class 2 felony, unless the weapon is possessed in the passenger compartment of a motor vehicle as defined in Section 1‑146 of the Illinois Vehicle Code, or on the person, while the weapon is loaded, in which case it shall be a Class X felony. A person convicted of a second or subsequent violation of subsection 24‑1(a)(4), 24‑1(a)(8), 24‑1(a)(9), or 24‑1(a)(10) commits a Class 3 felony.
(Source: P.A. 90‑686, eff. 1‑1‑99; 91‑673, eff. 12‑22‑99; 91‑690, eff. 4‑13‑00.)