Abstract: A pyrotechnic firing device for tools connected to a firing plunger movably mounted in a launch tube. The device consists of an inner barrel or frame (1), and a firing gas generator (9) housed in a modular breech (7) at one end of the launch tube (5) secured to a weight (3) which receives the recoil on the breech (7) during firing and is connected to one end of a damping cylinder (6) between the frame (1) and the weight (3). The device is useful as an easily adaptable and convertible firing device capable of being fitted with a wide variety of tools.