There are numerous articles on making this artillery piece.
This is most likely the M1841 version of the venerable Napoleon and was cast in bronze.
Barrel wight of 220lbs & with carriage totaled 500 lbs & shot a 12 lb shell.
Quite nice IMO
THIS is a 3" Ordnance Rifle, which is the top picture in the article, but is mislabeled. Another fine example of American journalism.
Rebel gunners were happy to hit a building with their cannon. Union gunners had rifled cannon, which could not only hit the barn, they could shoot out a particular window in the building.