A more involved (but better) method is described here. (Link to United Nuclear)
Another type of Torpedo/Impact Salute is made using silver nitrate. Click here. (Link to a Skylighter bulletin)
Here is a picture showing the construction of torpedoes following United NuclearÔø‡s procedure, but using BBÔø‡s instead of gravel.
These are some of the most fun, but most dangerous, fireworks you can make. If you do make them, extreme care must be taken. When you throw one of these against a hard surface they explode with a report and spray of match heads. You can use many different casings, but I prefer the hotel size shampoo bottles for these. They are a nice size and fit marbles well.
Warning! Blackpowder contains sulfur, and strike-anywhere matches contain potassium chlorate (KClO3). From Chem Info: "Potassium chlorate, or any chlorate for that matter, should never be used in combination with sulfur and sulfides. Mixtures containing both are very sensitive and may spontaneously ignite." If you do decide to make these, be very careful and use them as soon as possible to minimize the risk! The KClO3 is mixed with a binder on the match so not much will be exposed to the sulfur, but better safe than sorry. Be very careful if you make these!
Procedure:
1. Fill the casing with strike anywhere (SA) matches. Tap it down to fit as much as you can.
2. Fill the empty space with powder by putting some in and tapping
it down. Fill it pretty full, but not too full, because you need some
room for the matches to rub together.
3. Screw the cap on (Carefully!). When you shake the device, there should not be anything moving around inside it.
4. Tape it up very well. Make sure it is equally strong at all points.
To be extra sure it will go off, you can put in marbles. Put one in the end before filling, and one on the top. When thrown, they will smash together and set off the charge. I don't think the marbles are a big hazard because once I did one of these and found a marble only about 10 feet from where the device went off. Still you don't want them going off near you and you should always have eye protection.
Note: The matches will obviously be on fire and shoot in all directions. Do not use these were they can start a fire, such as around dry grass and stuff like that. I have started small fires with these, be careful!
