Set Trigger
Also: Double-Set Trigger
A trigger that can be pre-set to break at a very light weight, found on some target rifles and traditional hunting actions.
A set trigger lets the shooter prime the mechanism so the firing stroke breaks at a feather-light weight, often a fraction of the normal pull. On a double-set design there are two blades: one is pressed or pushed forward to set the system, and the second then releases the shot with the slightest touch. The appeal is a break so light that the shooter can fire without disturbing a carefully built position.
That low trigger weight is prized in deliberate, slow-fire target and varmint work, where every ounce of the trigger pull matters to the group. Set triggers demand respect, because once set they can fire with almost no warning, which is why most modern tactical and field shooters favor a well-tuned single-stage trigger instead.