V-3 Supergun

Developed as a vengeance weapon in order to strike back at London, as Allied bomber fleets pounded German cities to rubble, the V-3 (Vergeltungswaffe 3) cannon was capable to delivering a 140kg shell to a range of more than 160 km. The secret to this enormous range was a number of side channels attached to the 140m barrel. These channels each contained an electrically fired propellant charge which helped to accelerate the finned shell to a muzzle velocity of 1500m/s.

Hitler was most impressed by the prototype, and ordered 25 of them to be built at a site at Mimoyecques, in France. However, this site was heavily bombed by Allied bombers, which forced the Germans to abandon it. Two shorter-barreled 50m versions were later built and used against Luxemburg, where they fired a total of 183 shells, only managing to kill 10 civilians and injure 35. Shortly afterwards, both guns were captured by American troops.