The U.S. Supreme Court's first major Second Amendment gun case in a decade fizzled on Monday as the justices decided they no longer had a live controversy before them.

In a 6-3 unsigned opinion, the majority said New York City's rule limiting the transport of firearms within the city's boundaries was moot because the rule had been repealed after the justices had granted review to a challenge by the New York State Rifle & Pistol Association. The new city rule now allows the transport of guns to a second home or shooting range, "which is the precise relief that petitioners requested in the prayer for relief in their complaint."

The court declined to consider the rifle association's claims that the city's new rule still infringed Second Amendment rights and that the association could seek damages for the imposition of the old rule. Court observers had been closely watching the case, as it carried the potential for an expansion of Second Amendment rights.

Justice Samuel Alito Jr., joined by justices Clarence Thomas and Neil Gorsuch, dissented. They argued that the case was not moot. Alito, in his 31-page dissent, accused New York of manipulating the court's docket by changing the firearm transport rule after the Supreme Court had granted review.

"One might have thought that the City, having convinced the lower courts that its law was consistent with [District of Columbia v. ] Heller, would have been willing to defend its victory in this Court," wrote Alito. "But once we granted certiorari, both the City and the State of New York sprang into action to prevent us from deciding this case." Heller was the 2008 landmark decision establishing an individual right to possess a gun.

The case, Alito said, was not moot because the city's amended rule and a new state law did not give the challengers all of the prospective relief that they sought.

"We are told that the mode of review in this case is representative of the way Heller has been treated in the lower courts," Alito wrote. "If that is true, there is cause for concern." Alito, in his analysis of the Second Amendment claim, concluded that the city's rule did violate the Second Amendment. "This is not a close question," he wrote.

In a separate concurring opinion, Justice Brett Kavanaugh agreed with the majority that the case was no longer a live controversy, but he wrote that he also agreed with Alito's general analysis of the justices' 5-4 landmark Second amendment decisions in District of Columbia v. Heller and McDonald v. City of Chicago.

"And I share Justice Alito's concern that some federal and state courts may not be properly applying Heller and McDonald," Kavanaugh said. "The court should address that issue soon, perhaps in one of the several Second Amendment cases with petitions for certiorari now pending before the court."

New York City Corporation Counsel James E. Johnson said in a statement Monday:

"Today's  U.S. Supreme Court ruling in New York State Rifle and Pistol Association v. the City of New York is just right.  The Court properly recognized that the only claims the petitioners ever brought no longer present a live case, because the challenged City rule no longer exists. The question is, in a word, moot.  The Court's resolution was supported by plain common sense, the facts, and the law. We are pleased with the Court's decision."

The Supreme Court has other pending firearms cases on its docket. The cases include challenges to Massachusetts restrictions on certain semi-automatic firearms.

The high court recently turned away two gun-related petitions: Remington Arms's appeal of a Connecticut Supreme Court decision allowing a suit stemming from the Sandy Hook Elementary School mass shooting to go forward and an appeal of a circuit court ruling blocking a suit against Armslist, the online marketplace for firearms.

At the core of nearly all challenges by gun rights groups is the goal to have the Supreme Court announce a tough constitutional standard or test that governments must meet in order for firearm regulations to pass constitutional muster.

The case New York State Rifle & Pistol Association v. City of New York appeared to be in serious trouble during December arguments.

The city claimed the challenge was moot because the city last summer scrapped the ordinance that restricted the transport of firearms outside the city limits. The mootness question in the case arose after the justices agreed to review the case.

In the arguments, Justices Sonia Sotomayor, Ruth Bader Ginsburg and Elena Kagan repeatedly pushed back at comments by Alito and Gorsuch that suggested the court could still issue a ruling on the defunct regulations.

The city's restrictions limited the transport of guns—unloaded and locked in a container—from the home to any of seven designated shooting ranges inside the city. License holders could not transport their guns to shooting ranges or second homes outside of the city. After the city eliminated those restrictions, the New York General Assembly, amending state law, said premises-license holders could transport their handguns to any location where they are lawfully authorized to have and possess such a weapon.

On the merits, the gun association, represented by Kirkland & Ellis partner Paul Clement, had charged that the city's restrictions violated the Second Amendment, the commerce clause and the right to travel. The U.S. Court of Appeals for the Second Circuit had affirmed a district court decision in the city's favor on all counts.

Clement and Deputy Solicitor General Jeffrey Wall argued that the constitutional test should be whether the restriction comports with the Second Amendment's text, history and tradition. But the city's chief of appeals Richard Dearing endorsed the Second Circuit's approach of applying intermediate scrutiny—testing whether the regulation serves an important government objective and is substantially related to achieving that objective.