ban the private sales of firearms by making all sales between two private parties be conducted by a licensed ffl dealer

Right now in many states it is legal for the owner of a modern rifle or shotgun to sell that firearm to another person as long as the seller believes the buyer is at least 18 years of age. The buyer doesn't have to show any identification or have any kind of background check conducted. The sale of the firearm is treated as though the firearm is a bicycle or a wheelbarrow and not a potentially deadly device. By having the sale go through a licensed firearms dealer and having a background check conducted only law abiding citizens would be able to obtain firearms legally.