Connecticut gun rights groups, including the Groton-based Connecticut Citizens Defense League, have appealed to the U.S. Supreme Court to reverse the law, passed in 2013 in the wake of the Sandy Hook School shooting, that prohibits certain semi-automatic assault weapons.

The Second Circuit Court of Appeals in October upheld the constitutionality of Connecticut and New York gun laws, finding the prohibitions on semi-automatic assault weapons and large-capacity magazines impinge on Americans' Second Amendment rights but pass constitutional muster because of their goal of preventing crime.

The plaintiffs in Shew vs. Malloy contend, in a 486-page petition filed Thursday, that "Connecticut's flat ban on a class of constitutionally protected firearms that includes the most popular rifles in the nation is an unconstitutional infringement of the fundamental right to keep and bear arms."

New York groups also are appealing, according to Scott Wilson of New London, president of the CCDL.

He said the parties expect to know by June whether the high court will take up the cases.  

The New York appeal includes both the semi-automatic assault weapons ban and the law limiting the capacity of ammunition magazines to 10 rounds.

"Essentially our legal team is the same team that New York is using," said Wilson in a phone interview Friday. "We're trying a two-prong approach. New York is going for the full approach using the magazines. We are using a narrower challenge."

Connecticut's law, enacted in April 2013, added to the state's existing list of banned assault weapons, bringing the total to 183; limited the capacity of ammunition magazines to 10 rounds or fewer; required background checks for all weapon sales; and established a statewide registry for people convicted of crimes involving dangerous weapons.

Gov. Dannel P. Malloy has widely touted Connecticut's gun laws as the "smartest in the nation," saying they are designed to keep communities safe while respecting the Second Amendment.

The gun rights groups say the firearms in question are not assault rifles.

Wilson said in a press release that "they are common semi-automatic firearms that only shoot once when the trigger is pulled and are identical to others that are not included in the ban."

"Real assault rifles are full-automatic and can fire multiple times when the trigger is pulled," the press release said. "Real assault rifles are already highly regulated by both federal and state government, and civilian ownership is quite rare."

The lead plaintiff in the appeal is June Shew, an 83-year-old resident of Hartland, Conn.

Wilson said the NRA-ILA, which is the NRA's lobbying arm, has helped to assemble the attorneys, and that the lawsuit is being funded by groups like CCDL -- which has 21,300 members -- gun clubs and citizens at large.

k.florin@theday.com

Twitter: @KFLORIN