I can tell you what the Illinois State Police told me a few years ago when I was traveling from Texas to the communist sate of Illinois. They said if I was caught with a handgun in my possession, including my vehicle, it would at the very least be confiscated. They went on to tell me that if I were caught within the city limits of Chicago with a handgun (no matter what state it was in or where it was located) it is an automatic felony and I would be arrested. I believe that was true because I did some research on the subject in Illinois and their gun laws are very antiquated and anti-2nd Amendment. I hope that answers your question.
Cool. Hopefully someone will post what the real law is.
For example as a start:
http://www.law.cornell.edu/uscode/text/18/926A
18 USC § 926A - Interstate transportation of firearms
Notwithstanding any other provision of any law or any rule or regulation of a State or any political subdivision thereof, any person who is not otherwise prohibited by this chapter from transporting, shipping, or receiving a firearm shall be entitled to transport a firearm for any lawful purpose from any place where he may lawfully possess and carry such firearm to any other place where he may lawfully possess and carry such firearm if, during such transportation the firearm is unloaded, and neither the firearm nor any ammunition being transported is readily accessible or is directly accessible from the passenger compartment of such transporting vehicle: Provided, That in the case of a vehicle without a compartment separate from the driver’s compartment the firearm or ammunition shall be contained in a locked container other than the glove compartment or console.
Heck, even the Illinois State Patrol (who not are experts on the law) says this:
http://www.isp.state.il.us/foid/firearmsfaq.cfm
Non- residents must be legally eligible to possess or acquire firearms and ammunition in their state of residence. It is recommended that, in order to be in compliance with all statutes, non-residents transport all firearms:
Unloaded, and
Enclosed in a case, and
Not immediately accessible or broken down in a nonfunctioning state.
Is it legal to have ammunition in the case with the firearm?
Yes, so long as the firearm is unloaded and properly enclosed in a case.
and the applicable Illinois Statute:
http://www.ilga.gov/legislation/ilc...hapterID=53&SeqStart=65200000&SeqEnd=68300000
(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: (4) Carries or possesses in any vehicle or concealed
on or about his person except when on his land or in his own abode, legal dwelling, or fixed place of business, or on the land or in the legal dwelling of another person as an invitee with that person's permission, any pistol, revolver, stun gun or taser or other firearm, except that this
subsection (a) (4) does not apply to or affect transportation of weapons that meet one of the following conditions:
(i) are broken down in a non-functioning state; or
(ii) are not immediately accessible; or
(iii) are unloaded and enclosed in a case,
firearm carrying box, shipping box, or other container by a person who has been issued a currently valid Firearm Owner's Identification Card;