DENVER: A federal judge has blocked Colorado from enforcing a new law raising the age to purchase a gun from 18 to 21.US District Judge Philip Brimmer issued a preliminary injunction Monday following a legal challenge by a gun rights group. In a ruling that frequently referenced a US Supreme Court ruling that expanded Second Amendment rights last year, he concluded that the lawsuit brought by Rocky Mountain Gun Owners would likely succeed and barred the state from enforcing the law until the case is resolved.The law was...