Unfortunately, sometime back the US Supreme Court decided that lying on the 4473 was not chargeable because by answering the questions truthfully the purchaser may violate the 5th amendment, the right against self-incrimination.
Lord knows the Court makes bad decisions.
If I get dragged into a courtroom, put under oath and asked, “Did you rob a bank?” I think I have a right not to incriminate myself. Of course, if I choose to incriminate myself, I certainly can say, “I robbed that bank and 2 others.” I don’t have to do that, but I could.
If I make a decision to buy a product, and I go to a store that sells that product, and the proprietor asks me questions, I think I can choose to walk away and skip the whole thing, or I can make statements on a 4473.
If I don’t walk away, and if I make false statements, I think I have made a choice to incriminate myself. I didn’t have to, but I chose to.
I should be subject to the consequences.
I believe that ruling only applies to felons (No, I’m not kidding). A felon commits a crime by even touching a gun let alone trying to buy one. Charging him for lying when he checks the ‘No’ box on the 4473 asking if he’s a felon, is the self-incrimination bit.