The diameter is closer to 1 3/8 " and the strangest thing is that blue liquid that smells like paint is ozing out the opening in the end of the shell! The soil in my garden came from an area near an old dump on the Shamokin Trail in PA which was an old indian trail that dates back to colonial days which George Washington traveled! I don't think the "bullet" is that old but maybe quite a few years ago the area on the top of my hill was used as a target range. The dirt was dug from several feet underground.