1. A LIGHT GUN FOR LAUNCHING A PROJECTILE, SAID GUN COMPRISING A LAUNCHING TUBE, A SUPPORT SLIDABLY SUPPORTING SAID TUBE, A CASE ENCLOSING A REAR PORTION OF SAID PROJECTILE, A PROPELLANT CHARGE IN SAID CASE, A COUNTER RECOIL CHARGE CONNECTED WITH SAID BASE, SAID PROPELLANT CHARGE AND SAID COUNTER RECOIL CHARGE CONSTITUTING A ROUND OF AMMUNITION, A PRIMING DEVICE FOR FIRING SAID PROPELLANT CHARGE, A TRIGGER, MEANS FOR FIRING SAID COUNTER RECOIL CHARGE SUBSTANTIALLY IMMEDIATELY AFTER THE PROJECTILE HAS LEFT SAID TUBE, MEANS OPERATIVELY CONNECTING SAID TRIGGER WITH SAID PRIMING DEVICE AND SAID MEANS, MEANS PREVENTING GASES PRODUCED BY THE COMBUSTION OF SAID PROPELLANT CHARGE FROM PRODUCING A COUNTER RECOIL ACTION ON SAID TUBE, AND A REARWARDLY DIRECTED NOZZLE ENCLOSING SAID COUNTER RECOIL CHARGE FOR PRODUCING A COUNTER RECOIL ACTION ON SAID TUBE SOLELY BY GASES PRODUCED BY THE COMBUSTION OF SAID COUNTER RECOIL CHARGE.