DST or Double Set Triggers - On a rifle, optionally pulling the rear (set) trigger converts the front (main) trigger to a light, hair trigger. While the front trigger is always at the ready, if one has the time, using the set trigger feature may allow for a more accurate long-distance shot. To use this feature, the rear trigger must be pulled consciously just prior to taking the shot. It would be dangerous to walk with a loaded rifle having such a sensitive trigger as standard.
Operates using its own miniature firing mechanism (sear, spring and hammer) when cocked, to multiply the force of a pull on the main trigger. A pull of a few ounces then accomplishes the work that normally requires a pull of several pounds. A small setscrew located just in front of the set trigger adjusts the weight of pull of the main trigger.