From Under Iron Eyelids: The Biography of James Henry Burton, Armorer to Three Nations

Contrary to popular belief the Minie ball was not used by either side during America's Civil War. Instead infantry soldiers fired the Harpers Ferry bullet, a hollow based, cylindro-conical bullet designed by acting master armorer James Henry Burton. His reward was to be driven from his position by partisan politics and into the lap of Great Britain where he helped to establish the Royal Small Arms Factory at Enfield. Based heavily on Burton's own papers, this book explains the problems and solutions to the armory production of small arms. A complete inventory of machine tools used to manufacture the Springfield rifled musket is listed in an appendix along with details and diagrams of three patents awarded to Burton.