Two Fitchburg men have been charged in connection with an accidental shooting that sent a 16-year-old to the hospital with a gunshot wound to the abdomen. Authorities said Luis Robles, 25, and Efrain Molina, 24, both pleaded not guilty Tuesday to carrying a loaded firearm without a license. Robles is also charged with trying to intimidate a witness. Police say the men tried to hide the gun used in the shooting Sunday afternoon. The 16-year-old, from Leominster, is expected to survive. Police told The Telegram & Gazette that the teen at first told them he was the victim of a drive-by shooting. He later said he was visiting his cousin and had brought a semiautomatic handgun. While showing it to his cousin, he shot himself.