Not an unusual number when you figure the average gun a holic might have four hand guns in any one caliber. Then they figure they need one for each range, close, medium or far. Also, for each member of the family. And on it goes. So trading and swapping and selling firearms without a BC is a pretty normal activity. And lastly, there is the crew who for years has been afraid of the big Govt take over. Any thing goes. And lastly, firearms are an “investment” for them.
Hollywood has these guys pinned down. Bert Gummer in the Tremors series of movies is one. We all know at least one.