Small nit to pick - the 88mm gun we have is a naval cannon, not too major a gun - the famous 88mm Flak gun is another whole catagory, from the rifling characteristics, to the shell, to the use as an anti-tank weapon from the Spanish Civil War onward. At the ranges we fire, say 500m, that would be point-blank range - they were designed to shoot down aircraft many "angels" high in the sky ........
http://en.wikipedia.org/wiki/8.8_cm_FlaK_18/36/37/41