What Riflemen said.
They bust people here in Illinois often enough to keep it fresh in your mind. They nailed some guy for not abiding by the 24 hour waiting period when selling a shotgun in an ISP sting. The sting was in a ruralish area more than an hour outside Chicago. Not where you would expect such.
Abide by all State and Federal laws, you never know when the person standing opposite you is a Fed running a sting. Especially as gun control efforts fail in the congress, expert a lot more stings so the President can be shown to "do something about gun violence".
"....The swords of others will set you your limits".