Done (resetting) sorry - sometimes I forget with my monitor set to high resolution for CAD drafting.
I had some 4.5" cannon balls cast locally. A couple of hunded for the mould and then $16 each for casting. (sand casting) Some problems though - requiring a lot of hand grinding to round them out correctly.
When casting them (much larger than cast bullets in lead) they tend to shrink a lot - it isn't even. I've since learned that most folks put a core inside to make a thinner wall section and hence better control over shape when cooling.
Personally, when I get my shop wired, I'll scrounge some CRS in round stock and turn the spheres on the lathe. Summer maybe. I've just given two weeks notice at the best job I've ever had. Joining up with a enterprizing former student of mine (for 1/3 MORE than I was making) to work on belt-fed designs. Since he's got a couple of Mazak's we'll do some mortars and cannon as well.