U.S. District Judge Catherine Blake rejected arguments by a coalition of gun owners, retailers and manufacturers that the law is unconstitutional. She found legitimate arguments that the law, which took effect Oct. 1, 2013, increases public safety.
"The evidence demonstrates that assault weapons have several military-style features making them especially dangerous to law enforcement and civilians," she said.
The law limits the size of magazines to 10 rounds. After Adam Lanza, whose mother was a gun hobbyist, killed 20 children and six staffers at an elementary school in Newtown, Conn., gun control advocates argued that he was able to kill so many people because he did not have to stop to insert a new magazine.
Beretta USA, a subsidiary of the famous Italian gun manufacturer, announced earlier this year it was moving its Maryland operations to Tennessee.