An auto-reset dose release firing system (101) and a method of using same. The system can include an a stored energy device (109) a first plunger (103) movable between first, second, and third positions, the first plunger configured to be operatively coupled to a medicament canister (51) and a second plunger (104) movable between first and second positions the first and second plunger being movable with respect to one another and shaped to define an evacuable chamber (185) therebetween. The first plunger and the second plunger can move together from their respective first positions to their respective second positions, due to a reduced pressure in the chamber, to cause a dose release valve (54) to fire. After firing, air can be allowed to move into the chamber to allow the first plunger to move with respect to the second plunger to its third position to allow the dose release valve to reset.
