cannon ball ID

[fernando]

Sure thing; more precisely a grenade. Cannon balls are solid, grenades are hollow, to be filled with explosives or shrapnel. The loading hole also fits a fuse. Early ones were simply matchcord and later ones were 'inteligent' devices, like detonators and timers.
This one was possibly for a 2 1/2" howitzer.
18th or early 19th century, i would say.