Trigger bar

In a firearm action, the trigger bar is a flat metal piece that is used in some designs as a linkage between the trigger and the sear. The pressure ("pull") on the trigger through the bar causes a movement of the sear that releases the shot. Most modern semi-automatic pistols use the trigger bar in their actions due to the need for the trigger-sear linkage to go around the magazine.

The early small arms with matchlock used a long bar instead of a trigger. This bar is also known in the literature as a trigger bar. It was replaced by a short trigger resembling the modern one in the end of the 16th century, with its shape preserved for many more years in the outline of a trigger guard.