Sharp Shooters, formerly called Gilberts is off I-95 in Lorton, VA, just south of DC. I don't know if it meets your criteria for a "good" gun shop, but it sells guns and accessories and it has a range. You have to be a member to shoot, but you can get a 1-month membership for $12. It's close enough to DC that if you're staying in DC or VA, it would be easy to get in a couple of range sessions.
new website
http://www.sharpshootersva.com
Don't forget
NRA headquarters: museum, store, and range.
range url:
http://www.nrahq.org/shootingrange/nrahqrange/
museum:
http://home.nra.org/#/museum
I just googled "gun shops richmond va" and found these three just north of Richmond, and right off I95 (there were dozens of others, but not right off I95)
I know nothing about these stores - never been in them.
Greentop Sporting Goods Inc
10193 Washington Hwy
Glen Allen, VA 23059-1959
(804) 550-2188
http://www.greentophuntfish.com
Their website looks like it's geared for fishing - but they have a used gun inventory pdf file that's 20 pages long!
America Remembers
10226 Timber Ridge Dr
Ashland, VA 23005-8135
(804) 550-9616
http://www.americaremembers.com
a brief perusal of the website looks like they're all about special editions - might be fun just to look, but doesn't look like they're into "normal" gun sales.
Bass Pro Shops
11550 N Lakeridge Pkwy
Ashland, VA 23005-8047
(804) 496-4700
http://www.basspro.com
