The term "single-action" is a retronym that was not in use until weapons with double-action triggers were invented in the mid-19th century; before that, all triggers were single-action (for example, all matchlocks, flintlocks, muskets, etc.). While originally all hammers required a separate hand motion to cock manually, with the birth of repeating rifles such as the Henry rifle, it was found to be easy to design the cocking phase of the hammer into the cycling of the bolt. Although these weapons do not require the user to physically manipulate the hammer in addition to squeezing the trigger, they are still single-actions because the cocking is not performed by the trigger mechanism, which is only in charge of releasing the sear.