Looks like they're in the process of approving of semiautomatic pistols as well, instead of just revolvers:
http://www.examiner.com/a-1578585~DC_police_chief_concerned_about_House_gun_bill.html
http://www.examiner.com/a-1578585~DC_police_chief_concerned_about_House_gun_bill.html
While debate continued on Capitol Hill, the D.C. Council was set to consider an amendment next week that would make key revisions to the city's temporary gun legislation - including allowing residents to own semiautomatic pistols, council member Phil Mendelson said.
Most semiautomatic weapons have been prohibited under a D.C. law that bans machine guns - broadly defined as any weapon that can shoot more than 12 rounds without reloading. Mendelson said the language would be changed, though specifics are still being worked out.