While you're correct that this won't have any effect on state gun laws, the DC Circuit is much more than the equivalent of a state supreme court. Its rulings have an effect on DC obviously, but it also decides many cases arising out of federal agencies and their huge power. Because the federal agencies and government have power throughout the land, it is considered the most important Circuit Court in the nation. Decisons made there often do impact the entire country.
You are correct. I thought this decision was reached by the District of Columbia Court of Appeals, which is roughly equivalent to a state supreme court in the District of Columbia.
It wasn't. It was reached by the United States Court of Appeals for the District of Columbia Circuit. My bad.