Abstract: The powder actuated tool has a modular construction which comprises: a firing pin module; a pistol grip module; and a fastener driving module. The firing pin module and the fastener driving module are readily detachable from the pistol grip module so that if any module is damaged, or needs maintenance, it may be readily removed and replaced at low cost and at no inconvenience to the user. The fastener driving module includes a barrel which is reciprocally slidably mounted in the pistol grip module. A fastener driving piston is carded in the barrel and a piston return pawl is mounted on the pistol grip module for returning the piston from a fired position to a firing position via a slot in the barrel. Combustion gas ports in the barrel bleed gases from the barrel bore adjacent to the firing chamber. The bled gases pass through external grooves in the barrel to reentry ports communicating with the barrel bore, whereby tool noise is muffled.

Abstract: The powder actuated door lock-forcing tool has a modular construction which comprises: a pistol grip module; and a barrel assembly module. The barrel assembly module is readily detachable from the pistol grip module to allow interchangeability of different barrel assemblies which are specifically adapted to disrupt different types of door locks. The barrel assembly module includes a piston carried in a barrel, which piston is configured to be driven beyond the muzzleward end of the tool sufficiently to disable or disrupt a lock at which the tool is fired. The piston may have a cylindrical configuration or a flattened oval configuration at its muzzleward end.

Abstract: The powder actuated tool has a modular construction which comprises: a firing pin module; a pistol grip module; and a fastener driving module. The firing pin module and the fastener driving module are readily detachable from the pistol grip module so that if any module is damaged or needs maintenance, it may be readily removed from the rest of the tool and replaced at low cost and at no inconvenience to the user. The firing pin module includes a coherent breech assembly which is readily removable from, and securely attachable to the pistol grip module, which breech assembly comprises: a firing pin disposed in the breech assembly within a breech block; and cocking means extending from the breech assembly through the pistol grip module to engage the fastener driving module.