When I got my first all steel (carriage and barrel) golf ball cannon I realized that it would not fit into my small stainless mortar safe that I keep the rest of my pieces in so onto display mode in my house for the cannon. I had some painted, cast lead round balls to put with the display, but when I read about the steel golf balls here on GBO I decided to go that route. I first made two 25 hole plates (5X5) for the bottom layer to make a four sided pyramid (X2) so I did some math and ordered a large order of steel golf balls. While waiting I thought that I might have made a math error so I took my plates and cut through the middle of one edges row of holes so that both plates would mate together and instead of two pyramids I'd end up with a pyramid rectangle. Bottom row is 5X9, then 4X8, then 3X7, then 2X6 and finally for the top row 1X5. It looks awesome and I ended up with 5 extra balls. I had my son do some machining on the remainder to give me some bar shot for display.
After talking it over with my son and a lot of math I didn't realize that I'd forgotten already, I decided on one last ammo entry. The last entry is to be cased shot. So I knew the bore, I had to do some higher than I realized math to come up with the diameters of three smaller balls that would fit into that larger bore diameter. So I have the smaller steel balls and will order plain cotton duck canvas, safety wire, threaded rod, and some square nuts. I'll cut out two bore diameter disks from 11 gauge steel. It will have a central hole and three finer diameter holes to pass safety wire on both ends. I have the jigs made to stitch the cotton duck into a tube of correct diameter then the bottom plate will have six pieces of safety wire secured by the square nut on the outside of the plate with the central all thread going straight up. I'll then layer three balls per level interlocking between levels up to 5 levels total. The safety wire will rotate between the balls, three going clockwise and the other three going counter clockwise all ending through the top plate's three smaller holes (two wires per hole). I'll then use my aviation pliers to twist the safety wire to each adjacent hole. Once that's done, the twister wire will be bent towards the center bolt and be secured by a washer and another square nut. I have another bore diameter jig that will allow a perfect fit between twisted wire elongation and the top plate and nut's compression. Once secured it theoretically could be fired, but I'm doing it just for the display purposes.
I've been trying to think of other types of ammo shot out of the original cannon to build miniature replicas for my display, but the pyramid, bar shot, and cased shot are all I can think of so far. Smithy.
P.S. Pictures will show when I get all done.