Hi, Another on of my threads got me thinking, can I mix gun parts (ex browning reciever with remington barrel) to create a custom gun. I basically want to make a gun that is my design using already manufactured parts. Something like long barreled semi auto (ak, ar, ect) rifles, custom sniper rifles, ect. Is there any laws I should now about doing this (I do not plan to sell)? Do I need a FFL? Am I just crazy for thinking about doing this?