The gun bill was passed on a busy legislative day that also included votes in favor of bills allowing adoptees to access their original birth certificates; creating a commission to study college affordability, and requiring certain police vehicles to carry video recording devices.
Family members of two children slain at Sandy Hook traveled to Trenton in support of the magazine restriction.
"These tragedies can be reduced if not eliminated by passing legislation like this," Assembly Majority Leader Louis D. Greenwald (D., Camden) said at a Statehouse news conference following the vote.
"My children will be safer, and your children will be safer, if we do this and if we learn the painful lessons from these families."
Greenwald said reducing the maximum magazine capacity would force gunmen to reload more frequently, giving would-be victims a chance to escape and allowing authorities to apprehend the shooter.
Gun-rights advocates testified at legislative hearings this year that the bill would place law-abiding gun owners at a disadvantage to criminals, who are unlikely to comply. They also denounced the bill - which would also prohibit semiautomatic rifles with a fixed magazine capacity exceeding 10 rounds - as a gun ban that would infringe on their Second Amendment right to bear arms.
"This legislation only impacts law-abiding citizens and will not stop another crime or prevent another tragedy," Scott Bach, executive director of the Association of New Jersey Rifle and Pistol Clubs, said in an e-mail Thursday.
The bill was recently amended to exempt certain "beginner" guns and to establish a 180-day grace period to exchange, surrender, or render inoperable guns and magazines made illegal under the bill.
Six states and the District of Columbia have 10-round limits, previously the national standard under the 1994 assault weapons ban. That law expired in 2004.
"I hope and believe the governor, who is a father himself, will do the right thing and sign this bill," Greenwald said.
Kevin Roberts, a spokesman for the Republican governor, said the legislation "will be carefully examined in the 45-day review period we have prior to taking action."
Last year, Christie approved some anti-gun-violence legislation, such as increasing penalties for gun trafficking, but vetoed others, including a ban on .50-caliber weapons.
In other legislative action, the Assembly passed a bill that would require some municipal police vehicles to be equipped with mobile video recording systems. The recorders would have to be installed on the dashboard or worn by an officer.
The bill would apply only to new police vehicles that are used primarily for traffic stops, and the devices would be funded by surcharges imposed on people convicted of driving while intoxicated.
Christie let the bill expire last year without taking action on it.
"He hasn't given us any direction," said Assemblyman Paul Moriarty (D., Gloucester), explaining why he reintroduced the bill this session.
In July 2012, Moriarty was arrested on suspicion of driving while intoxicated, but video evidence later showed he had done nothing wrong. The police officer who pulled Moriarty over was indicted on criminal charges last year.
The bill still must pass the Senate, which, like the Assembly, is controlled by Democrats.
Also Thursday, Senate President Stephen Sweeney (D., Gloucester) announced that he would attempt to override Christie's conditional veto of the senator's Hurricane Sandy "Bill of Rights" legislation.
The bill would require the state to establish a searchable system so applicants for recovery aid can track their applications, grant applicants the right to appeal certain unfavorable decisions, and establish the right to fair access regardless of race or ethnicity, among other provisions.
Christie sent his revisions to the Legislature last week, and in his veto message described Sweeney's bill as "a series of post-hoc mandates that are violative of state and federal law, rife with illegal priorities and unquantifiable administrative costs, that would prove impossible to implement, frustrate sound future disaster planning, and all but certainly exceed federal funding for program administration."
The bill passed unanimously in both houses.