Phelps WMA has a great range, free, but it's only 100 yards. It's near Sumerduck, and worth the drive. Get there early, as it's first-come basis for a bench. If there are waiters trying to get a bench, shooters are supposed to use their bench for an hour, then pack up and give up the bench. Doesn't always happen, and if you hit the range in the middle of the week, you might be the only one there sometimes.
http://www.dgif.virginia.gov/wmas/range_rules.pdf
http://www.dgif.virginia.gov/wmas/detail.asp?pid=17