Zarco Macross: German Railgun

How powerful was the 800mm Gustav gun? - Quora

Trivia: Gustav Max was based on Schwerer Gustav, the rail cannon made and used by the nazi germany, also considered the largest gun ever used in a war. : r/DuelLinks

Schwerer Gustav, Wiki

Dora/Schwerer Gustav K. (E) Rail Gun, World War II Wiki

German Railgun - Zarco Macross

Krupp K5 - Wikipedia

Which modern gun can outmatch the WW2 800mm Schwerer Gustav? - Quora

Sturmtiger II, The Wolfenstein Fanon Wiki

A Shell and a Cartridge of the Schwerer Gustav Rail-Canon from WW2 in the Military Museum in Dresden. - 9GAG

Schwerer Gustav - The Greatest, And Most Useless Gun Ever Put Into