Twenty-four-year-old Cory Dion Caldwell of Waterford is to be arraigned in New London Superior Court on Tuesday.
Waterford police arrested Caldwell at his home Monday because of an investigation by the Naval Criminal Investigative Service, which had received a tip about Caldwell. Authorities say they seized the AK-47 along with ammunition, a .50-caliber handgun and two .45-caliber handguns.
Caldwell was held overnight on $200,000 bail. There's no phone listing for him and it's not clear if he has a lawyer.
The Georgia native is assigned to the USS Springfield based at the Naval Submarine Base in Groton.