Complex sentence: Challenger 1 achieved the longest confirmed kill of Gulf War 1, destroying an Iraqi tank with a DU round over a distance of 5,100 metres (over 3 miles)--the longest tank-on-tank killing shot ever.
Split into simpler sentences: Challenger 1 achieved the longest confirmed kill of Gulf War 1, destroying an Iraqi tank with a DU round over a distance of 5,100 meters (over 3 miles). The longest tank-on-tank killing shot ever.