While I was on the Gatling gun binge, I noted that the heavy "1-inch" Gatlings produced just after the Civil War, had a "buck & ball" ctg, as well as what may have been a true "cannister" cartridge.
Wow, can you imagine the effect that would have on the battlefield of the time!!!
Here is an interesting experiment I'd like to see with that load-out. Take a couple hundred barrels filled with water and spread them around a field. Then turn loose a couple of heavy gatlings shooting cannister.
If the American Civil War had happend 10 yers later, there may well have been trenches all along the mason-dixon line.