Folks. This is a shot for shot put--a track and field event. This is an older style shot I have seen in high school. It has an outer shell of brass or steel, and a slot screw cap to fill with lead to bring it up to exact weight. A similar shot was identified a few years ago as a Nelco brand brass shot, 4 kilograms, which are still being sold in track & field supply catalogs today. It was found in a person's back yard in NJ, and the Atlantic City police bomb squad still thought it was a cannonball and "detonated" it. It was a more modern shot with the two spanner wrench holes (similar to some bicycle rear hubs) in place of the older slot screw design.