MELTING COPPER CASTING COPPER COINS WITH HOMEMADE STEEL MOLD

I machined a solid piece of steel at work and wondered if it would make a good mold ,so today I'll try and pour molten copper into the steel mold. I'm sure of the work perfect but let's see. I have thought about a basic stamp to just mark these coins , something pretty simple to start with. I was going to machine up a piece of steel much like this mold but a bit bigger that would just sit on top like a lid and once I pour the metal while it's still red hot but not quite set I would put the larger mold lid on top and hit it with a big bloody hammer . I would have a simple design in the lid mold to stamp into the top of the ingot . Alternatively I could engrave a design in the base of the steel mold I pour into (obviously it would be a mirrored design so it transfers the right way around once the ingot is removed) .