You can buy on line but you will have to have it received by a licensed dealer that is local to you or at least in your state. Many on line dealers maintain a list of FFLs they have dealt with in the past. Your best bet is to call the dealer and he will walk you through it. As to person to person sales they must go through an FFL also but can be more tedious since you now have to usually deal with two different FFLs, one in each state. If person to person with both residents of the same state you have to follow state laws.