Here in France, I seem to be unable to get parts for cannons. All the plumbing parts here are metric. I need help here in finding the right sizes in MMs. Secondly this might mean changing the size of the ball bearings!? What are your thoughts on all this? it would be a pity to only buy cannons from the US of A and get the steel balls from the UK and not make our own!
Since copper piping comes in varied sizes, I'd determine what the diameter of your ammo is, then locate tubing & fittings that match.
