Not true. If you're crossing state lines, an FFL transfer needs to take place.

From the ATF website:

(B3) May an unlicensed person obtain a firearm from an out-of-State source if the person arranges to obtain the firearm through a licensed dealer in the purchaser’s own State? [Back]

A person not licensed under the GCA and not prohibited from acquiring firearms may purchase a firearm from an out-of-State source and obtain the firearm if an arrangement is made with a licensed dealer in the purchaser's State of residence for the purchaser to obtain the firearm from the dealer.