For me this has been a very interesting post.I own a J & W Tolley, 12 bore, damascus hammer gun. It is marked " UBIQUE " and " For Spherical Ball". The Bores measure .715 end to end. The gun has a folding rear sight marked for 60 Yards. It has been nitro proofed for 2 3/4 inch shells.

I assume the right diameter balls to use would be exactlly bore size. You have shown me where to get them.Thanks.