WASHINGTON — The Supreme Court on Wednesday seemed ready to strike down a restrictive New York gun permitting law, but the justices also seemed worried that a broad ruling could threaten gun restrictions on subways, bars, stadiums and other gathering places.The court was hearing arguments in its biggest guns case in more than a decade, a dispute over whether New York’s law violates the Second Amendment right to “keep and bear arms.”Chief Justice John Roberts and other conservative members of the court, which has a 6-3 …