It depends on what state you go to. They check driver’s licenses and have different state laws at hand to check. I remember several years ago when buying just a box of .22’s in Illinois the clerk checked my DL against a list of states. I could buy ammo in Illinois being from the state of Washington but people in IL couldn’t buy unless they had a license to buy ammo. Weird.
I prefer living in a place where there’s some ammo just out on the shelves ready to buy, and NOBODY cares.