SACRAMENTO, California: Intending to raise some US$160 million per year to help prevent gun violence, California Governor Gavin Newsom signed into law this week a first-in-the-nation state excise tax on sales of firearms and ammunition.

Due to come into force in July 2024, the California excise tax will add an 11 percent levy on top of the existing federal excise gun and ammo tax, a rate of 10 or 11 percent, depending on the type of weapon.

Part of a package of gun safety bills approved by Newsom, the measure was implemented four days after a federal judge rejected a California ban on high-capacity ammunition magazines, ruling that it unconstitutionally infringed on gun owners' Second Amendment rights.

His action on gun safety came in "the wake of shootings across the country that have left at least 104 people dead over the past 74 hours," Newsom's office said.

In a statement, Democrat Newsom said, "While radical judges continue to strip away our ability to keep people safe, California will keep fighting because gun safety laws work."

Data showed the rate of gun-related deaths in California, home to some of the most stringent firearms laws in the country, is more than 40 percent lower than the national average, he added.

The excise tax would be collected on the gross receipts of California manufacturers, retailers, and dealers from local gun and bullet sales.

In a statement on social media platform X, gun rights advocacy group the California Rifle & Pistol Association said it had already filed a "preemptive lawsuit" against the measure.

Supporters of the new tax highlighted a 2021 report by gun control advocates that found gun deaths and injuries cost California $22.6 billion each year, of which $1.2 billion is paid directly by taxpayers annually.