1. IN AN AUTOMATIC ROCKET LAUNCHER OF THE TYPE WHICH INCLUDES A RECEIVER FORMED WITH A FIRING CHAMBER, THE IMPROVEMENT WHICH COMPRISES, IN COMBINATION: A BOLT MOUNTED FOR RECIPROCAL MOVEMENT RELATIVE TO SAID FIRING CHAMBER, THE BOLT ADVANCING FORWARDLY INTO BATTERY TO CHAMBER A ROUND OF AMMUNITION AND RETRACTING REARWARDLY TO PERMIT A NEW ROUND TO BE PLACED IN POSITION TO BE CHAMBERED; RELEASABLE LOCKING MEANS FOR LOCKING THE BOLT IN BATTERY POSITION; OPERATING MEANS COMPRISING A PLURALITY OF SPACED MEMBERS CONSTITUTING A TROMBONE-LIKE SLIDE AND MOUNTED IN RECIPROCAL MOVABLE RELATION TO AND SYMMETRICALLY AND EXTERNALLY DISPOSED RELATIVE TO SAID BOLT, SAID OPERATING MEANS RETRACTING REARWARDLY TO ACTUATE SAID RELEASABLE LOCKING MEANS TO UNLOCK SAID BOLT; COMPRESSIBLE MEANS MECHANICALLY INTERCOUPLING SAID BOLT AND SAID OPERATING MEANS, SAID COMPRESSIBLE MEANS BEING COMPRESSED WHEN THE OPERATING MEANS RETRACTS REARWARDLY, WHEREBY TO STORE ENERGY TO RETRACT THE BOLT WHEN THE BOLT IS RELEASED; AND STRAINABLE MEANS MECHANICALLY INTERCOUPLING SAID OPERATING MEANS AND SAID RECEIVER, THE STRAINABLE MEANS BEING STRAINED WHEN THE OPERATING MEANS RETRACTS REARWARDLY, WHEREBY TO STORE ENERGY TO ADVANCE THE OPERATING MEANS AND THE BOLT.