I remember my brother taking me to gunshops in Leesburg and Front Royal about 6 years ago before he retired from the Pentagon. You might do a computer search for those shops to see if they survived. Quite a ways from Fort Belvoir, but a REALLY nice part of the world to drive in this time of year.
He also frequented a shop and range called Clark Brothers in the Virginia side of the DC area, which you might look up to see if they are still with us.
There was a nice shop in Leesburg (Nimrod), but its been closed for a long time. Clark Brothers doesn't have any doubles worth driving to see IMO and David Condon in Middleburg has some nice stuff but to say they are priced high is (IMO) and understatement. There was also a nice shop in Front Royal, but the owner passed a few years ago and it closed as far as I know. Old Dominion in Winchester often has some nice doubles and last I knew was a Merkel dealer. They do have some nice high end stuff with I think real world prices. You can find an occasional nice gun at GreenTop down towards Richmond. They have moved to a much large store about 2 years ago.