Another possibility is the use of smokeless powder.
That is also a possibility I hadn’t thought of. Too powerful and too many times..............
I considered that, what with the difficulty in obtaining any kind of gunpowder these days.
The cannon the homeowner fired was similar to a Signal Cannon, more commonly used as a novelty item. Police said the homeowner bought the cannon at an auction prior to the event and had fired the cannon several times before.
"The cannon is designed to create a big flash, a loud noise and create smoke," Michigan State Police said in a news release. "The cannon did not contain any projectiles, but it is suspected that the gun powder loaded into the device caused the cannon to fracture, resulting in shrapnel being spread in the area."