I don't know DC...when I tote mine in the duffel bag, I throw the duffel on the cart first and stack the rest of the luggage on top with some of the other luggage filled with ammo. Nobody gave it a glance because it looked like a pile of luggage.
When I went to Pcola, one of the reasons I took weapons(besides, I always do), was because as I drove over the bridge the first time my uh-oh-dar went off. Wow, this is the only bridge here...one way on...one way off. So I carried some "support" across with me...especially after 9-11...I heavy-ed up some. I could imagine some terrorist blocking the bridge on the island side, preventing help from getting across whilst others went up and down the beach on a killing spree or entering the buildings and starting at the bottom killing their way up. With four bent on killing...they could do some damage.
As it was...there was Bubba in his room playing "overlord" to the beach for 600 yards in either direction. People always ask...can you really shoot someone from 600 yards...maybe that's less likely for me due to aging and lack of practice but I can shoot at them, whether I hit them is another matter. Hit or not, I can get close enough to give em something to think about besides killing other folk.