UPDATE! It works.. prints nicely in two pieces. My support on the top shell didn't stick and was a little ugly but sanded out ok. If you can provide support for the threads at the bottom and remove the center support for the top section it will print great.
To create a Stencil for your shell check this out:
I know you wanted it.. so here it is.. the 155MM Howitzer Shell with a side of split body and your choice of Fuzes, Solid and Slotted.
But wait, there is more! Instead of a snap-to body, I threaded it so you can screw the top and bottom together. Yes.. that happened.
This will print on a printer that can do 320MM or less BUT it does it takes about a roll of filament to print!
I will post pics when it get one printed. I will also build and upload a stencil so you can paint it to standard.
If your new to 3D Printing you will probably want to check my profile for my 3D Printing tips. There are some good shenanigans in there.
If you need Olive Drab PLA: http://amzn.to/2Dnkk6R
Good quality white: http://amzn.to/2n0KPYP
Good quality black: http://amzn.to/2G6ozpp