[Still Thinking]

That's not field gun, THIS is a field gun (not really, cause it's rail mount)

31", shoots 28 miles

[SJSAMPLE]

Those things proved to be a huge burden and clusterfuck. Took rail lines and dissassembly/reassembly to move and position. Hundreds of crew and support troops. Insane logictical trains to support. And they were non-moving targets. Artillery survives by being MOBILE.