A 30-06 bullet can travel over 3 miles when fired at a 45 degree angle. When shot straight up they can reach over 300 feet per second by the time that they return to earth. Close to a third of people struck by celebratory gun fire die compared to 6% to 7% of those killed by bullets being fired at them. This is because most victims of celebratory fire get hit in the top of the head.
Even further if 30 degrees.