In other words, it won’t do anything to stop another mass killing.

Via NY Post:

New York’s new law limiting the number of bullets in semiautomatic rifle magazines won’t stop determined mass killers, firearms experts said yesterday.

It takes six to eight seconds to fire off a 30-round magazine like that used in the Newtown killings, said Joseph Green, a retired firearms instructor and agent of the federal Bureau of Alcohol, Tobacco and Firearms.

A well-trained shooter would need roughly 13.5 to 22 seconds to fire off the same number of bullets with six magazines of five rounds each, which are legal in New York.

A shooter needs 1.5 seconds to swap out each cartridge, and each five-round cartridge takes one to two seconds to shoot.

Killers facing stressful situations — such as a lot of screaming people — might need a bit more time to swap cartridges, Green said.

But he and other experts say swapping magazines means just a minor delay for determined mass killers.

“It’s not difficult for someone proficient to change magazines. It will take you a few more seconds, nothing longer,” said John Cerar, a retired NYPD deputy inspector and former head of the firearms-training unit.