Boxlock action

The popularity of boxlock actions declined rapidly after the emergence of percussion cap and pinfire revolvers in the mid-19th century.

Boxlock actions have the advantage that they are more compact than side mounted lock mechanisms, which made them a popular choice for pocket pistols.

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.

An 1882 improvement incorporated a trigger block safety, which was automatically engaged when the hammers were cocked.