Here are my three artillery pieces. I haven't figured out what calibre they are, neither do I really care. Normally I make sure to post it, but I didn't model these after anything, so they are just Lego arty. That's all...
About this creation
Here is my biggest cannon complete with a caisson trailer for extra ammunition and equipment (such as shovels for digging in.
A side picture of the caisson and rear of cannon
Just the caisson showing the front area for a rider or more equipment
The ammunition case
The cannon deployed with stabilizing arms expanded. The small part is the arm latch that would then be attached to the caisson.
A front shot of the gun showing the armour plates. The barrel clips in to keep it stable for transportation
Close-up of the breach. Nothing impressive, just some random levers and wheels...
My next smallest cannon with a transportation arm attached. It also has tools for levelling the deployment ground