Ever seen a movie where people get shot? Want to know how to make reallistic looking gunshot wounds without getting charged for murder? The answer is squibs. Squibs are simply small explosive charges placed under the clothing, and electrically exploded in sync with a fake gun.
I won't provide instructions on how to implement squibs for reasons of safety and laziness, but I will show you how to make them.
Pick out your favorite brand of firecrackers. I just happened to have these laying around.
Seperate the individual firecrackers from the string. Try not to damage the fuses.
Carefully pull out the fuse. This is the hardest part: all too often it snaps off, leaving you with a dud. For best results, loosen the clay surrounding the fuse by chipping it with a pin or crushing with a pliers, then extract in one firm pull. Only pull once, as multiple small pulls seem to break it.
Select your wire. I use 24 gauge twisted pair taken from an old cat5 ethernet cable. Anything smaller will overheat, and anything larger probably won't fit.
Strip the insulation off the ends of the wire. As you can see, make one wire a centemeter shorter than the other, then strip 5mm off of each. (Metric tape measures are a pain to find in the US. Idiotic imperial sheep.)
Take a small pair of pliers and bend the stripped portion in half to form a small loop.
Make a loop on the end of the nichrome wire, and loop it around the shorter wire.
Starting with the nichrome, close the loop with the pliers. Do the same with the lead wire, first closing the loop, then crimping the nichrome tight. Don't try to solder. It won't stick to the nichrome, and the oxide formed by the solder could break the circuit.
Bend the second wire loop over the nichrome and crimp it. No need to make another loop in the nichrome. Cut off the excess nichrome.
Carefully push the wire assembly into the fuse hole of the firecracker, using the pliers when nessesary. Try to avoid twisting.
Continue pushing until the wire assembly is fully inserted to the original depth of the fuse.
Affix the wires the the firecracker using your favorite adhesive. (Notice my clever juxtaposition.)
If waterproofing is desired, dip the entire squib in nitrocellulose laquer once the glue has dried. Avoid any air bubbles. (Yeah, crappy pic. It makes it look cool though.)
Hang the squib up to allow the laquer to dry.
If you wish to use your squibs to simulate gunshots in clothing, you will need to make a metal shield to shape the charge. Using a scrap of sheet metal, cut out a shape approximately like this.
Fold on the dotted lines, and hopefully you will have a shape like this. Tape up the edges to prevent gas from escaping. Simply place the squib inside, and tape it to the inside of the clothing.
If everything works well, it should produce a nice realistic looking bullet hole in the fabric. Be sure to use an extra metal plate for protection if you decide to use this on live subjects.
Here is a clip of squibs being implemented in my friend's movie. Poor guy. We had him lying on the cold ground in the rain, covered in chocolate syrup with explosives strapped to his chest for nearly half an hour. We shot him with a 9mm pistol. Then we used the squibs. Good times...