For anyone interested in seeing what Civil War Artillery could really do, Paulson Brothers Ordnance Company has some great video of original Civil War Cannon firing explosive shell at Fort McCoy, Wisconsin. The video includes field artillery plus some of the big boys - including a 13 inch siege mortar. Check it out!
The website is: http://www.pbocorp.biz/
click on the action button to see the videos.
PS: In the video of the 3 Inch Ordnance Rifle and the 30 Pounder Parrott on the barbette carriage, both guns are being manned by Turner's Battery, Company C, 1st Mississippi Light Artillery, of which I was a proud member.