I do not know your local, county, or state laws so I am not telling you this is legal, only that Federally this is not illegal as long as you NEVER store this after mixed, use it commercially, attempt to set it off with blasting caps or other devices, and only use it for range related activities utilizing common sense. If you mix up 50 pounds of this stuff, put it on a large propane tank, and the resulting fireball breaks windows across town, you are going to be held liable. However, if you keep it small, and shoot it at a range you will probably be okay.
However, do not take my word for the legal status, I am not a lawyer, and take no liability for things you do. You can look up the BATFE’s interpretation of the law in their free “orange book” or follow this link to see exactly what the Fed’s say about exploding targets.
That being said, what we made here is not “tannerite” tannerite is a trademarked name, and the mixture contains a couple additional ingredients than just Ammonia Nitrate and Aluminum powder. But you can get similar results just using the two main ingredients.
It is a very simple mixture:
100g Ammonia Nitrate to 5g Aluminum Powder.
For those interested, here is the formula:
X * 0.05 = Y
X = Weight of AN
Y = Weight of AL to mix with that amount of AN
50 pounds of AN = 22,679.6185 grams, so using the above formula:
22679.6185 * 0.05 = 1,133.980925
1133.980925 grams = 2.5 pounds of AL
So for every 50lb of AN you purchase you will need around 2.5lb of AL.
Or if you want to spitball (which is not recommended when dealing with energetic materials) for every pound of AN, use 2 tablespoons of Aluminum powder.
I used instant cold packs, as buying Ammonia Nitrate in bulk is near impossible for the general public after Oklahoma City. If going this route, make sure the package ingredients lists ammonium nitrate. Urea nitrate WILL NOT WORK.
Once you are at your range mixing is easy. Carefully slice open the cold pack without rupturing the water package inside, add 2 spoonfuls of powdered aluminum, mix thoroughly and then seal. I like wrapping everything tightly in colored duct tape. The tight wrappings keep the mix from leaking if hit with a glancing shot, and the color helps me see what I am aiming at.
This is very simple, and when used with common sense it is relatively safe.
There are some practical uses of this mixture. It is especially useful for long range shooting, as there is no doubt of your hits, but above its practical uses, it is a lot of fun, just make sure you research your local laws, and use an uncommon about of common sense.