If they catch you with it loaded, ANYWHERE, there will be a problem. My men had one in their hotel room. it was confiscated, even though they had a legal right to have it, were licensed in the home state, the whole bit. Took hours to get it back, and were "detained" while they searched every jot and tittle of the law for an excuse to arrest them.
We HATE Illinois, as all law-abiding citizens, across the country should.