The boxlock action is a hammerless action of a type commonly used in double barreled shotguns, dating back to 1875. The boxlock action was developed by Anson and Deeley, based on the earlier Westly-Richards action. The boxlock action uses concealed, self cocking hammers in a break-open action. Strongly opposed by most sportsmen and manufacturers at first, the boxlock action quickly become the dominant form of double barreled shotgun action.[1][2]
The boxlock action was the result of a long evolution of hammerless actions, created by two gunsmiths, Anson and Deeley, working for the Westly-Richards company in 1875. The contribution of Anson and Deeley was in the simple and elegant lock mechanism, which provided a hammerless action with fewer moving parts than exposed hammer models available at the time. This allowed a rugged and simple action which was faster to operate than exposed hammer guns. The original model, pictured above, used a hammer block safety, which was problematic, as it was possible for the gun to discharge when the safety was released. An 1882 improvement incorporated a trigger block safety, which was automatically engaged when the hammers were cocked. This type of automatic safety is still prevalent in modern boxlock actions.[3][4]