I've never shot at a Great Barracuda because Tahiti is the only place I've seen them.
The biggest I've been next to was in the 5 foot range at Hotel Bora Bora, it was barking at the reflection of my Nikinos lens after materializing right aside of my wife's shoulder. We were only in about 15 feet of water. The fish moved like something out of the Matrix.:@
Here in Cali we only have the Pacific Cuda (slime stick) my old cat loved them, and I smoked a few that I shot when target shooting/testing . I dig diving down into balls of them in Baja...Cuda tunnels.
Cheers, Don