If you want to see some video footage of a 3" Ordnance Rifle firing double canister at a series of targets, get a copy of The Learning Channel's program entitled: Unsolved History: Gettysburg - Pickett's Charge. Several types of rounds were fired live for that program, but unfortunately they all did not make it into the final cut. The double canister from the rifle is featured, however, and is quite impressive. It made one heck of a spread and sounded as if a bushel basket of pocket change had been hurled downrange when it rattled through the trees at the far end of the range. Just an FYI.
CAM