I caught this in August of 2005 at Fort Gaines. We're in the fort's blacksmith shop, about 250 feet away from a group of reenactors firing a small brass cannon replica.
I wish I'd gotten some close pictures and video, but the cannon guys went on break almost as soon as I walked across the parade ground.
They started firing again--of course--once I went outside the fort to get pictures.
Might want to keep the volume down--especially after you hear "Fire in the hole" the second time.