1. A PORTABLE INFANTRY GUN, COMPRISING: A FIRST TUBULAR MEMBER DEFINING AN ELONGATE, OPEN-ENDED PASSAGE HAVING A STRAIGHT AXIS AND FORMING CHAMBER AND FRONT BARREL PORTIONS OF THE GUN; A SECOND TUBULAR MEMBER DEFINING AN ELONGATE, OPEN-ENDED REAR BARREL PASSAGE FOR THE GUN AND HAVING A CURVILINEAR AXIS THE TWO EXTREMITIES OF WHICH ARE INCLINED TO ONE ANOTHER AT AN OBTUSE ANGLE OF THE ORDER OF 150* TO 140*, THE REAR BARREL PASSAGE HAVING THE SAME SUBSTANTIALLY UNIFORM BORE ALONG ITS ENTIRE LENGTH; AND MEANS SO DETACHABLY ENGAGING THE CHAMBER PORTION OF THE FIRST TUBULAR MEMBER WITH THE SECOND TUBULAR MEMBER AS TO JOIN THE PASSAGES WITH THEIR AXES IN ALIGNMENT AT THE JOINT AND FORM A CONTINUOUS OPEN-ENDED TUBE WITHIN THE GUN; AND A UNITARY ROUND LOADED WITHIN THE CHAMBER PORTION OF THE GUN, THE ROUND COMPRISING A PROJECTILE OF LARGE MASS RELATIVE TO THE MASS OF THE GUN; A CUP-SHAPED GAS CHECK ON THE REAR END OF THE PROJECTILE ADAPTED TO SEAL THE FRONT BARREL PORTION; A THIN-WALLED CASING CONTAINING A QUANTITY OF SMALL SHOT AND ADAPTED TO PASS ALONG THE CURVED REAR BARREL PASSAGE; A SECOND CUP-SHAPED GAS CHECK ON THE FORWARD END OF THE CASING ADAPTED TO SEAL THE REAR BARREL PASSAGE; A PROPELLANT CHARGE ENCLOSED BETWEEN THE TWO GAS CHECKS, ADAPTED WHEN FIRED TO PROPEL THE PROJECTILE FROM THE FRONT BARREL PORTION WITH LOW MUZZLE VELOCITY OF THE ORDER OF 1000 TO 1200 FEET PER SECOND AND TO PROPEL THE CASING AND SHOT FROM THE REAR BARREL PASSAGE, WHEREBY, IF THE GUN IS ADJACENT THE GROUND AND THE FIRST TUBULAR MEMBER IS SUBSTANTIALLY HORIZONTAL, THE PROJECTILE TRAVELS IN A NEARLY FLAT FORWARD TRAJECTORY TO EACH A TARGET WITH SUBSTANTIAL ENERGY, AND THE SMALL SHOT TRAVELS IN A CURVED TRAJECTORY OBLIQUELY UPWARDS AND THEN DOWNWARDS TO REACH THE GROUND WITH A NON-LETHAL VELOCITY, AND THE FIRING IS ACCOMPANIED BY ONLY VERY LOW EMISSION OF FLASH FROM THE FRONT BARREL AND REAR BARREL; AND MEANS CARRIED BY THE CHAMBER PORTION FOR FIRING THE PROPELLANT CHARGE.