triggering piston 16 is sufficiently greater than the surface area of firing piston 20 such that the net downward force on triggering piston 16 causes shuttle 18 to move downward until the surface of firing piston 20 contacts the perimeter of lower chamber 24 with reference to fig2 b initiation of air gun 10 includes activation of solenoid 26 and injection of high pressure gas between triggering piston 16 and upper chamber 14 through chamber passage 28 the sudden introduction of gas through solenoid 26 disrupts the equilibrium state of gun 10 causing shuttle 18 to move upward at a high velocity passage of firing piston 20 past ports 30 rapidly releases the gaseous volume of lower chamber 24 the electrical current operating solenoid 26 is provided through conduit 34 waveforms 36 generated from the rapid high pressure release of gas from lower chamber 24 propagate through the mass of water medium 38 within well bore 42 as shown in fig2 a and 2b preferred embodiments of gas guns of the type utilized in accordance with the present invention can include one or more deflectors for the purpose of concentrating or focusing the percussive waveforms on a specific target or area within the well bore as shown in fig2 a and 2b deflectors 32 are secured to gas gun 10 in a manner sufficient to withstand the waveform impact and permit them to.