A federal judge in Virginia on Wednesday declared unconstitutional a set of federal laws and regulations that prohibit federally licensed firearms dealers from selling handguns to 18- to 20-year olds, finding the measures violated the Second Amendment. “Because the statutes and regulations in question are not consistent with our Nation’s history and tradition, they, therefore, cannot stand,” U.S. District Judge Robert E. Payne, who sits in Richmond, concluded in a 71-page opinion. Attorneys on both sides of the case said they expected the Justice Department to appeal the decision and request a stay, which would prevent Payne’s ruling from taking...