You've been told I don't know how many times that gun shows require background checks, but you keep on posting that leftist canard.  You are either not paying attention, or you are lying to a crowd of people who know better. 
I type in real time,  and if I misrepresented the facts regarding transactions at gun shows, I apologize.    I don't frequent such events.   
But my point remains valid  -  private sales should be effected through the medium of a licensed gun dealer,  because the gun dealer has an economic incentive to police the transaction 
Here is a statement that I found on-line:
 Currently, federal law requires background checks (through the National Instant Criminal Background Check System) only for guns sold through licensed firearm dealers, which account for 78% of all gun sales in the United States. 
Do you disagree with it?   Facially, it appears that 22% of all gun sales do not involve background checks.  What is your objection to closing this loophole?