Amin
What you have described on some of our purchases, is true and yes, it can go that way. However, I and several others that I know, don't work this way. Every state is somewhat different but for our state and if it's a handgun, I do not sell to anyone that does not have a permit to buy. I note their name, address and their permit number. There have been a few buyers that have refused to deal in this manner and that's perfectly fine with me and I thank them for their time. I don't have any but if I did, I would only sell a Black-Gun, through an FFL dealer and I pay the cost of that transaction.
Now, if it's a rifle or shotgun, I only get his name. If it's an M/L, all I need, is the cash. ....
Understand that this is my personal requirements to myself and oh yes, there is no Gun Show loophole !! ....
What I or others do on private sales, has no affiliation with the Gun Show of it's promoter. To make that connection is wrong. ...
Be Safe !!!