http://jamesdjulia.com/item/2210-391/

The Spiller & Burr was a copy of the 1854 Whitney revolver, made in .36 caliber under contract to the CSA. As with so many Confederate arms projects, many thousands were promised and only a small fraction actually delivered. The Whitney in particular suffered from a lack of suitable materials, with cylinders having to be made from twisted iron instead of proper steel.

http://www.patreon.com/ForgottenWeapons