First. welcome to the forum. As said, firearms law varies state to state, and YOU did not share that with us.
With the exception of National Firearms Act weapons (machineguns, silencers, sawed offs, destructive devices) there IS no Federal registration of firearms. MOST states do not require it, SOME require handguns be registered, etc.
There are special rules for transfer of an INHERITED firearm across a state line in the Federal law. Under 18 USC 922, the executor of an estate can ship a BEQUEATHED firearm across a state line directly to the person inheriting it, so long as the person recieving can possess that gun, and it is legal in their home state. In all other transfers, when crossing a state line, would have to go to a dealer in your home state to be transferred to you.
Tell us the details, and we could direct you to a real answer.
What we have here is... failure- to communicate.