Republicans complained the measure was rammed through the Legislature and infringes on the Second Amendment right to bear arms.
"A lot of people say, 'Why do you need these guns?'" said Assemblyman James Tedisco, a Schenectady Republican. "It's part of the freedoms and liberties we have. ... It's for our public safety. It's to protect us from our own government."
He said the bill was dangerous because it would give people a "false sense of well-being."
"You are using innocent children killed by a madman for your own political agenda," he said. "You are actually making people less safe."
Tom King, president of the New York State Rifle & Pistol Association, questioned whether other states or the federal government would follow New York's lead and said he expects the law to be challenged in court.
Previously, New York state law on assault weapons banned semiautomatics that have detachable magazines and at least two military-type features, such as a pistol grip, folding stock, muzzle flash suppressor or bayonet mount. The new law outlaws weapons with just one of those features.
It also requires background checks for even private gun sales, except those among immediate family.
In addition, it says handgun owners must renew their licenses every five years, and it increases prison sentences for using guns in various crimes or taking them onto school grounds.
"By making this a priority, the governor has not only saved lives but will hopefully inspire leaders in Washington also to take swift action," said Dan Gross, president of the national Brady Campaign to Prevent Gun Violence.
In a concession to the pro-gun side, local authorities will be allowed to withhold the identities of registered gun owners — an issue that erupted recently when a suburban New York City newspaper published the names and addresses of gun owners in its readership area.
The New York legislation sparked spirited discussion among customers at the Buffalo Gun Center in the suburb of Cheektowaga, where business was so brisk that people had to wait in line in freezing temperatures just to get in the door.
"It's ridiculous. It's absolutely — how to put it nicely — it's Prince Andrew Cuomo's bid for the White House," said Jim Hanley, who was waiting to buy another handgun. "I want to do it before the right is taken away. Andrew Cuomo and Barack Hussein Obama are two best gun salesmen in the history of the world."
Associated Press writers Michael Gormley in Albany and Carolyn Thompson in Buffalo contributed to this report.