here-
Go to Radioshack. buy:
Speaker Wire
A mono-type headphone jack connector (male)
2 large-diameter speakers (can be salvaged, must work)
Wire the speakers together, so that the corresponding contacts are connected. then, take one of the speakers and run that connection to the mono connector. then, to test, plug the mono- jack into the headphone port, turn the volume up on your computer all the way, and blast some music. if you hear sound out of both speakers, youre set. plug the mono connector into the michrophone port. turn on the recorder thing, and record your gun firing. if you want to test, record yourself tapping the speaker.
there ya go. pretty straight foward.......... i should have explained before