A blowgun for efficiently and accurately launching subcaliber projectiles comprises:an elongate barrel;a detent comprising a magnet affixed near the proximal end of the barrel and a protrusion partially obstructing the bore breech;an associated conical shell discarding sabot; andan associated subcaliber projectile having a magnetically attractable foreshaft and a lightweight elongate shaft. The source and reception signals are separately subjected to preprocessing 2 and psychoacoustic modelling 3. The pressing member presses the recording medium against the conveyance belt at a position between the conveyance roller and the image forming unit. The payload support frame is supported at its first and second ends by a wheel-based support assembly and a mower-based support assembly, respectively. The packing structure can protect a battery from external impact while minimizing an increase in size of the whole battery.