The artillery keeps rolling in to this QTH! This piece arrived just today. The bore is roughly 12mm and is clear all the way back to the touch hole, although the bronze barrel has much hardened residue for the length of the bore. The metal trimming was heavily rusted, and the wood absolutely filthy. But after an hour or so with 3 in 1 oil and fine wire wool, it was soon looking much better. The barrel will be left as it is, there is no point in removing all that patina. Barrel is almost eight inches in length. Overall length is 10 inches by six inches high. .303 round stood next to cannon for reference to size. Now where did I put that black powder???