What will happen if you are caught violating the promoter's rules is 1) you will be told to leave the premises, 2) you may be told (in writing) that you are forever forbidden to enter any of their promotions anywhere in this or any other world, 3) depending on their mood they may or may not ask you to pose for a picture so they can post your likeness where the ticket-sellers are located, or 4) they may or may not get your likeness from one of the many security cameras and post your picture where the ticket-sellers are located. At least that is my understanding in talking with several of the reps from the promoters who bring the gun shows to RIR and The Showplace.
For some unknown reason they do not bother with steps 2, 3 and/or 4 with folks arrested at the shows.
If the shows get to the point that there is no difference between getting in to a gun show and getting on a plane I am fairly convinced that attendance will drop to the point that it is no longer profitable for the promoters or the vendors to show up.
What still amuses me is that even with the "No Loaded Clips or Magazines" I can still go in, buy clips or magazines and ammunition, and assemble them. This puts the "it's because of insurance requirements" line to the point of straining believability. Either that or the underwriters are in fact morons.
stay safe.