Military-style assault rifles such as the one used in the San Bernardino massacre would be banned from sale or transfer in California under legislation introduced Thursday.
Supported by state Atty. Gen. Kamala Harris, the proposal would outlaw guns with "bullet buttons."
"We must close the loopholes in our assault weapons ban so that guns like the ones used in San Bernardino, Newtown, [Conn.] and Aurora, [Colo.] cannot be bought legally in our state," said Assemblyman David Chiu (D-San Francisco), a co-author of Assembly Bill 1664, introduced by Assemblymen Marc Levine (D-San Rafael) and Phil Ting (D-San Francisco).
If the legislation passes, all rifles sold in the state would have to have permanently affixed magazines.
Harris supports a second bill, Assembly Bill 1663, that would ban bullet-button guns and require current owners of guns with bullet-buttons to register them as assault rifles. Both proposals drew immediate opposition from gun advocates, including Sam Paredes, executive director of Gun Owners of California.
"There are tens of thousands of these guns in the possession of law-abiding citizens in California, and they are not using them in crimes," Paredes said.
Previous attempts to ban such weapons either stalled in the Legislature or were vetoed.
Harris' involvement -- as well as the terrorist attacks in San Bernardino -- could give the effort added momentum.
"The devastation wrought by gun violence on innocent victims, children and families in this country, is an international embarrassment," Harris said in a statement. "This is a common-sense solution that closes a dangerous loophole in California's assault weapons ban."
The state outlawed the sale of assault rifles in 1989, and has limited the capacity of magazines sold to 10 bullets. But the ability to replace magazines in seconds has been seen as a way to get around the ban, said Amanda Wilcox of the California Chapters of the Brady Campaign to Prevent Gun Violence.
"We support the goal of AB 1664 to finally close the loopholes in a manner that will prevent the firearms industry from continuing to sell these lethal military-style weapons in our state," Wilcox said.
A bill vetoed by Gov. Jerry Brown three years ago was much broader -- not only barring semi-automatic rifles with magazines that were detachable by any means, but also requiring owners to register some low-capacity rifles as assault weapons.
That bill is similar to the new AB 1663.
In his veto message, the governor wrote that he didn't "believe that this bill's blanket ban on semi-automatic rifles would reduce criminal activity or enhance public safety enough to warrant this infringement on gun owners' rights."
The new legislation goes too far, according to Brandon Combs, president of the Firearms Policy Coalition.
"We've seen these types of attacks on semi-automatic firearms in the past, and we've defeated those. So we are cautiously optimistic that the Legislature and governor will see through this," Combs said.