Am I correct in remembering that you can legally travel through any state with an unloaded gun in your trunk out of reach of the driver/passengers?

I think I read this a year or so ago. Like if I have an unloaded, unchambered handgun locked in a combination safe in the trunk of my car is that federally legal to travel through any US state?What if I can technically access it by laying down the backseat? via /r/CCW https://ift.tt/2SV0Eyt