If people are interested in the type and amount of training that goes into making distance shots when they count, I recommend Andy Brown's
Amazon.com
Here's a decent account of the incident:
www.historylink.org
The Cliff notes:
"Meanwhile, Senior Airman Andrew P. Brown, age 25, with the 92nd Air Force Security Police Squadron, was patrolling the base’s housing areas on a bicycle when he received an emergency call on his two-way radio. He pedaled a quarter-mile to the scene and, while still some 70 yards away, spotted Mellberg shooting at scores of panic-stricken people in the parking lot.
Brown ditched his bicycle and ordered the gunman to drop his weapon. When Mellberg turned and shot at him, Brown dropped into a combat crouch and returned fire with his 9mm Beretta M9 semiautomatic pistol. He fired four rounds at Mellberg; two missed, one hit him in the shoulder and one struck him between the eyes, instantly ending his homicidal rampage. The drum magazine in Mellberg’s MAK-90 still held 19 rounds of ammunition."
In the book I linked, Andy Brown describes in great detail his training regimen prior to the shooting. Again, four rounds from an arms-room issued Beretta M9, two hits, one fatal from seventy-two yards away. It was the first and last time he ever fired that particular gun.