[No Truce With Kings]

Ah . . . if it blew up it was not a cannonball. It was a shell.

A cannonball is a solid chunk of metal. A shell is a hollow sphere filled with explosive. They look different — and even if you cannot tell by looking at it (due to corrosion hiding the fuse hole), a shell would be lighter than a cannonball of the same size.

First rule of restoration: Know what you are restoring.

[attiladhun2]

Also what they called bolts shot from rifled breech loading artillery. They are cylindrical and often made of lead. They were solid or hollow and filled with powder. Most fired did not explode. Luckily they are rare.

[labette]

"First rule of restoration: Know what you are restoring. "

Bingo. And another rule: "A little knowledge can be a dangerous thing."