When I lived down in Falls Church, I was a member of tidewater muzzleloaders, who meet and shoot up near Marriottsville, MD. Clark Brothers gun shop south of warrenton VA, has or had a range out back. (Gotta buy ammo from them to use the range) The NSSA will be having their Spring National's soon. Just North Of winchester VA. (Go watch those boys shoot their cap and ball revs, for some truly amazing shooting) As I recall there was a black powder club out near Manassas. Another club over near Denton MD. I heard there was or are ranges open to military personnel at Ft Mead, Ft Belvoir and Quantico.
Also check some Sass sites for local clubs.