Wow, those 11" guns were such large caliber that they could penetrate better than most of the 13's of their time.

Krupp have been banned from making armaments twice, after the first and again second world war. The scale and deadliness of thier war machines in the 2ndWW was such the allies after the war again banned them. They today develope other massive feats of engineering in the mining industry and after u take alook at this beast, Manufactured by Krupp, and in its native Germany, - http://www.swapmeetdave.com/Humor/Workshop/Trencher.htm - u will begin to wonder what they could have made, and what it is still possible to make in terms of land warmachines. Ofcourse there is also the japanese projects of developing a 'Mech' type of giant robot warmachine, nice..

The largest calibre gun actually put in a tank would probably be the Centurion AVRE, with a 165mm demolition gun firing HESH. The Churchill AVRE fired a 290mm projectile, but that wasn't a gun, but a petard mortar. The Sturmtiger wins the calibre contest though, provided one is looking for direct fire and allows a) rockets and b) Self-propelled guns