A trigger assembly for activating a firing mechanism. The trigger assembly includes a trigger having a sear arm with a first sear surface, and a firing element including a body portion with a second sear surface and an engagement portion for engagement with the firing mechanism, for activating the firing mechanism. The trigger assembly also includes a captured roller positioned for engagement with the first and second sear surfaces. The trigger is pivotable between a load position, in which the captured roller is held between the first and second sear surfaces, and a release position, in which the second sear surface is disengaged from the captured roller and the firing element is released. The firing element is pivotable between a first position, in which the firing element is held by the captured roller, and a second position, in which the firing element is disengaged from the captured roller.