Transporting a firearm on Amtrak from Union Station

Hello,

trying to determine the legality of taking a firearm (properly locked up and unloaded) from Virginia into WDC for boarding a Westward bound train (end in Fargo ND). I know its legal to transport a firearm on Amtrak provided its locked up in checked baggage. What I am concerned about is presenting a checked bag in Union Station and having to declare you have a firearm inside.

Amtrak's rules are you must call them 24 hours in advance and let them know you are transporting a firearm, and then abide by all their policies.

I would personally seek the advise of a qualified attorney.
DC, NJ, NY and a few others play by their own rules.

Have you considered shipping the firearms (since you can't carry it on your person anyway).
You can legally ship your firearm from you to you via contract carrier to the address you are going.