During an unpleasant time in my life, I was an ALO attached to an armor battalion. We were doing a night live fire exercise so 105mm main guns, .50 caliber, 25mm chain guns, TOW missiles, and, the winner for spectacular effects and crowd pleaser, APC mounted 20mm vulcan shot at ground targets. As a Hawg driver, we talked a lot about big sky, little bullet theory but, to quote the military historian Ho Lee Fuk, "That's a whole lot of metal going a long way uphill via richochets." The big, fast stuff like 105mm and TOWs had to be topping out better than 1000 feet on occasion. Seeing that stuff bounce at night really changed my thoughts on pressing hard target slant range cease fire distance.