In the era before the Colt Single-Action Army revolver, chain-driven guns were all the rage. Epenetus Bennett and Frederick Haviland of Maine collaborated on this prototype chain rifle—it was so unique it was awarded Patent No. 603 in 1838.
The .40-caliber revolving rifle features 12 individual chambers—each holds a powder charge and a lead ball. To prevent the possibility of chain fire, the percussion cap is protected by a plate covering the round in the chamber.
The rifle was nicknamed “The Underhammer.” As each shot was fired, one of the 12 brass chambers that were hinged along the chain would be brought into line with the breech by rotating the crank wheel on the underside of the receiver.
The gun submitted to the U.S. Patent Office was a miniature model and only 10 full-scale models were ever manufactured. This very rare, extremely unique—and quite expensive—gun represents an interesting phase in firearms evolution.