You see that circle in the middle of the ball, that is a fuse.
Many fuses of the era look like mushroom headed electrical fuses.
That also means the ball is filled with black powder and maybe shrapnel balls.
I bought a "cannon ball" from a flea market and got books from the local library. Did my own research on cannon balls. Turns out I was snookered: it was a solid grinding mill ball, even though the dimensions were close for a 12 lb Napolean.
After determining it was just a round mass of cast iron, I brought it to work. After telling the story of how I found "the cannon ball" and how it might be fused, I usually managed to somehow drop the thing on the floor. Word got around.
The funny thing was now, in my community, I was now a Cannon Ball expert, and others brought in their cannon balls for identification. One guy had a solid shot 6 pounder he had dug out of his back yard.
Another guy brought his cannon ball. It was a Parrot I think, long and with four ridges at the base. He bought it around Gettysburg. The seller told him it had been defused. And that was a true statement. No fuse in the forecone. However, you could look through the cavity of the shell and see that it was packed with powder and iron balls. The thing still had the original charge!
I told the bud 1) He needed to take it home , 2) keep it well away from any sources of ignition, 3) and wash the thing out with hot water to dissolve the powder.
Hope I gave him good advice.
I remember talking to an EOD guy at a local gunstore . He had all sorts of cannon ball stories, only one I remember. He had been called out to a little old ladies house to look at her civil war cannon balls. They sounded identical to the pictured round shot. Round and fused, loaded with an explosive charge, and sitting on either side of her fireplace!
People are still drilling these civil war cannon balls and getting killed by them. I kept a newspaper clipping from the 70’s of an Antique Dealer at Gettysburg. He took a dug up CW shell and was doing something with it in his shop. Killed him.
The last CW fatality is still decades ahead of us.
If I'm not shooting, I'm reloading.