What you mention about selling a private gun at a gun show is part of the basis of the leftist lie. Yes, it can occur, but it is no different than putting an ad in the ‘Thrifty Nickel’, then meeting at the McDonald’s parking lot to do the exchange to do a private transfer.
The gunshow is just the location where it is done, but it is NOT part of the show itself. And rather than taking an ad out in the ‘trader’ paper, the advertising is wandering around the parking lot (or sometimes inside the show) with a “for sale sign” on the gun.
If I remember my ATF regulations correctly, it is legal to do private transfers like that three times per year. Any more, and you are required to get an FFL.
Yes, the grabbers lie by omission there.