- Single Action
A method of fire in some revolvers and shoulder arms in which the hammer must be cocked by hand, in contrast to double action inwhich a single pull of the trigger both cocks and fires the weapon. In revolvers, any gun whose hammer must be manually cocked for each shot. In semi-automatic pistols, any pistol where the hammer or striker must be manually cocked before the first shot can be fired.
Single Action Revolver, Ruger
1873 single action Rifle and Revolver