The present invention relates to a gun (1) with a pair of barrels (6′, 6″) flanking each other, each delimiting a cartridge chamber (12′, 12″). The gun further comprises a pair of firing pin tips (8′, 8″) for a cartridge (10′, 10″), movable towards the cartridge chambers (12′, 12″) by means of a firing device operated by a trigger (4′, 4″); such device acts on the firing pin tips to allow a substantially simultaneous advancement thereof. The invention also relates to a two row magazine for a double barrelled gun.