I suspect a large part of the reason RI ranks the worst is simply because it is so tiny so not a lot of people to but guns to begin with (although growing up on Newport Naval Station there were always plenty of southerners with gun racks :) ). As far as the industry, not a lot of industry (or employment) of any kind -- I know people who commute from RI to Boston.
Newport Naval Station brings in a lot of gun-toting south
Rhody is filled with Unions that are dependent on the Government for Everyone’s needs. The Citizen’s own needs , the bazillion illegals that live there..see Cape Verde, and the Teacher’s Union. 65 percent of the population is on the Government tit.