Was wondering if there are any plans for building the barrel to be used for making a replica WWII M2 or M19 mortar with a black powder barrel that will shoot golf balls or maybe one that would do tennis balls? I have very little knowledge on cannons or mortars so help would be appreciated. I have seen a couple of these mortars on various videos but there is little info associated with them. Have heard about using seamless pipe but am not sure where to get it or what ID, OD and wall thickness to use. Also, info on the interior design for the combustion chamber? Thanks for any help. Mike