Here is something about ..
BIG gunsUsed for hunting ..Tigers and Leopards - and Bears ( and other such things )
Who would have ever thought that in that sad muddy little isle one would be allowed to own such things ?
Made me think of Crocodile Dundee - "This is a knife"
https://youtu.be/GGPxesCB8ns
They had a few such weapons building up to this.
I remember the one big gun had side chambers filled with propellent that ignited as the missile passed. These added chambers edged the shell to greater speeds and filled the loss of expansion caused by the extremely long barrel.
The extra charges were there because the barrel was so long that the bullet travel along it caused loss of pressure, the pressure was topped up so to "along the way"
https://www.youtube.com/watch?v=Yfgbm_0QGbU&pp=ygUecmFpbCBndW5zIG9mIHRoZSAybmQgd29ybGQgd2Fy
https://youtu.be/X1qWVjtDn9I
Think about what it took to make them ? How much / many scarce resources were used up
Always the German problem .. bigger is better
Russians understood the theory that quantity brings it's own quality
See siege of Sevastopol ( where this weapon was used )
Many people know about STALINGRAD not many know about SEVASTOPOL - which was perhaps worse and more important
Very much currently in the news