Authorities said the boy thought the gun wasn't loaded when he put it up to his temple and pulled the trigger.
According to Capt. John Gallagher, the incident occurred while the teen was web chatting with an as-yet-unidentified individual who challenged his "manhood."
"His manhood or his ego was challenged and he said something along the lines of ‘I'll show you'," Gallagher told the local Daily News. "He thought he was clowning around, trying to shock the other party on the Internet site."
The gun belongs to the teen's 22-year-old brother who was in the room at the time along with their other brother, a 13-year-old. Both were asleep at the time.
Police are investigating whether the gun was obtained through legal means and are still attempting to establish contact with the unknown chat partner.