Still, to this day, not one of my guns has murdered anyone. NFATCA delenda est!
The standard US flechette is 1" long and 0.05" in diameter and weighs 13gr.
The tungsten ball in an M1040 canister round is 0.31" in diameter and weighs 73gr.
For some reason this was harder to find than it was the first time I looked it up.