Questioning the legality of tactics used by New York Mayor Michael Bloomberg to sue gun dealers, a federal judge in Atlanta has allowed a defamation suit by a Smyrna, Ga., gun shop against Bloomberg and other New York City officials to go forward.

Senior U.S. District Judge J. Owen Forrester rejected arguments by New York officials to dismiss the suit brought by Adventure Outdoors Inc. — one of 27 shops, eight of them in Georgia, facing Bloomberg’s suit in New York.