Three young adults are suing Minnesota officials, saying current law requiring no one under 21 to carry a gun is unconstitutional.  The two 18-year-olds and a 19-year-old filed a suit in federal court, along with Minnesota Gun Owners Caucus, Second Amendment Foundation and Firearms Policy Coalition, Inc., against county sheriffs and the MDPS commissioner.  Their lawsuit says Minnesota age law violates the 2nd and 14th Amendments while also applying unfairly to young women.  In response, some anti-gun groups say it is the right of the state to create some gun restrictions.