Military Gun Salutes | The Daily Caller

"Three Volley Salute
"One misconception is calling the shots fired at a military funeral a 21-gun salute. Even if there are seven soldiers firing three rounds each, this is not a 21-gun salute, because the soldiers aren’t using guns, they’re using rifles. In the military, guns are considered artillery. Instead, the shots fired during a military funeral are called the firing of three volleys in honor of the fallen"