There are ways to close the “gun show loophole” without making it nigh-impossible for regular people to transfer or sell a gun occasionally. It could be as simple as a law stating “if you sell more than 5 [or 10 or 20] guns in one year then you are considered a gun dealer and must conduct background checks”. That by itself would close most of the “loopholes” that are often criticized, while allowing you to give a gun to your nephew, or sell your old revolver, without hardship.