Not all companies responded in the same way to the development of cartridge revolvers and the Rollin White patent. Allen & Wheelock, for example, decided to simply ignore the patent and make revolvers for their proprietary lipfire cartridges (fairly similar to rimfire) while relying on their lawyers to delay the anticipated patent infringement suit for as long as possible. Ultimately it took 4 years for Rollin White and S&W to gain a legal injunction against them, and when that did happen they were ready and converted their production to percussion revolvers of the same basic type. This particular piece is a .36 caliber ("Navy") version for the lipfire round, which have been since converted to use either lipfire or more common rimfire ammunition.