I was watching the sniper Vs sniper show again when I realized that there was one problem. The scope that Gunnery Sergeant Carlos Norman Hathcock II shot the NVA sniper through a Russian made Mosin Nagant scope which is in fact much smaller (shorter) than many other scopes, so the bullet from Hathcock's rife could have penetrated through the scope of the opposing NVA sniper.

Thanks, Tigertrack18