The present invention relates to a small-calibre defence system, characterised by the use of an unconventional process, with the following main characteristics: the absence of a trigger and hammer, which are replaced by firing mechanisms in the form of a handle (B) inside which the percussion system (C) is activated by rotating it in relation to the barrels (E), thus forcing the striker to move up a ramp thereby compressing the tensor system, after which it is released and the firearm is detonated, this merely being an example of what the invention covers; the novelty of its design, which has been devised in order to make it difficult or impossible for a child to activate it; it is assembled longitudinally in multiple barrels (E), with a manually tightened rotating safety lock (D), contrary to the buttons and catches of similar firearms; it has a integrated Progressive Impact Area Indicator laser sight (F) which functions progressively according to distance; and it has a foldaway grip (G).