Arguing that California's Assault Weapons Control Act infringes on the Second Amendment, the state's NRA affiliate filed a lawsuit on Monday challenging the ban's constitutionality.
At the rest of the yearly NRA conference - held this year at the Georgia World Congress Center, near CNN headquarters - guns are allowed.
The California Rifle & Pistol Association filed a lawsuit against the state Monday in federal court targeting six laws that took effect January 1.
The first suit was to be filed late Monday in federal court in Santa Ana by the NRA and its affiliated California Rifle and Pistol Association, asking the courts to declare the expanded assault-weapon law unconstitutional.
Michel said the NRA plans five lawsuits against the laws.
The National Rifle Association, the parent organization of the Fullerton-based group that filed this week's suit, has promised to take on California's gun control laws, including last November's Proposition 63, the successful state ballot initiative backed by Lt. Gov. Gavin Newsom.
"The Secret Service works closely with our local law enforcement partners in each state to ensure a safe environment for our protectees and the public", the agency said in a statement.
"It criminalizes possession of firearms which are commonly possessed for lawful purposes by law-abiding citizens for self- defense or shooting sports", Chuck Michel, a Long Beach attorney for the gun rights groups, told the Los Angeles Times.
California's laws limited handgun purchases to one a month, expanded the gun sale waiting period to 10 days and required a background check on all ammunition purchases.
State officials rebuffed the lawsuit.
The Pennsylvania state House wants to enable gun owners and groups such as the National Rifle Association to launch legal challenges to cities' firearms regulations. The groups rank low in total spending on lobbying the state Legislature, with less than $400,000 total spent a year ago.