Trigger (firearms)

A trigger is a mechanism that you pull on a firearm to shoot. Triggers almost always have levers or buttons for the index finger.

Trigger (firearms) Media

Trigger mechanism in a bolt action rifle: (A) trigger, (B) sear, (C) striker spring, (D) striker.
Thompson submachine gun trigger
The double-crescent trigger on the MG 34, which enabled select fire capability without using a selector switch. Pressing the upper segment of the trigger produced semi-automatic fire, while holding the lower segment of the trigger produced fully automatic fire.

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