Patent ID: 7753042

Claim:
A mechanism adapted for use in a gas-operated gun of the type having a housing, a trigger and a source of fluid under pressure fitted to the housing, the mechanism comprising a sleeve adapted to be fixed relative to the housing, a hollow bolt slideable in the sleeve between a retracted position and a firing position when the trigger is actuated, the hollow bolt comprising a wall having an inner surface defining a hollow interior thereof, the sleeve comprising a chamber surrounding the bolt, said wall having bores there through communicating the chamber with the hollow interior, the wall of the bolt when in the firing position having an outer surface segment that isolates the chamber from the source while permitting fluid communication between the chamber and the interior of the bolt through the bores and wherein the wall has a second segment that, when the bolt is in the retracted position permits fluid communication between the chamber and the source of fluid under pressure while the chamber is isolated from the interior of the bolt.