Highly doubt there is enough energy in a non DD 37mm round to set off tannerite.
Tannerite is a "Bianary Explosive", meaning unmixed the two separate ingredients are not regulated as explosives. Once mixed, and capable of going BOOM, they become an explosive just like any other as far as the regs go. Magazine storage, transport regs, etc. Mix up one too many targets, your only option at the range for most folks is shoot it or pour it out on the ground and spread it out.
Here's ATF' summary of Binary Explosives:
https://www.atf.gov/explosives/binary-explosives
MIXED tannerite is an explosive just like TNT, PETN, C4 etc. and is treated the same as to regulations. UNMIXED tannerite is not an explosive and thus does not have to follow any of the explosives regs. To use it in a shell it would have to be mixed, thus you are putting an explosive into the shell.
Take your TNT example, I can go out and buy Toluene and Nitric Acid at a chemical supply store. no explosives regs apply as neither component is an explosive by itself. However, I follow the process for nitrating the Toluene three times to produce TNT, the final product is regulated as an explosive. Tannerite is following the same process, raw materials to explosive, but is a much simpler "shake and bake" type of procedure. In both cases the final product is an explosive and is treated as such legally.
why dont you shoot the tannerite in a pile with a concussion 37mm round, a direct impact should trigger your desired resultsJust curious, is it legal to use Tannerite to load 37mm (or other sizes) projectiles, or would they have to be registered with ATF?
Would they even explode on impact?
Or would they explode when fired?
why dont you shoot the tannerite in a pile with a concussion 37mm round, a direct impact should trigger your desired resultsTannerite is a binary explosive. A binary explosive consists of 2 ingredients (or multiple ingredients in two separate components) that are not considered explosives by themselves. However, once mixed they become an explosive and will detonate. The advantage of binary explosives is the unmixed components can be shipped directly to anyone, no explosive use permit required as is needed with explosives in general, no explosive magazine storage required, etc. Once mixed however, all the storage and transport rules apply which is why you mix it on site and use all mixed targets.
Anyone who mixes a binary explosive is considered to be manufacturing explosives. however, much like making your own guns, if you are doing it for private use (blowing stumps in your backyard, playing at the range, etc.) you are exempt from needing an explosives license. Commercial use (selling it, using it to take stumps out as part of your tee business, etc.) does require the license.
https://www.atf.gov/explosives/binary-explosives
37mm launchers are generally considered to be signal devices, not firearms or NFA at all. However, possessing "anti-personnel" ammunition along with a launcher classifies it as a Destructive Device.
All the above is Fed law, state and local laws vary and I'm pretty sure some localities have at least tried to ban exploding targets.
BTW, the "recipe" for Tannerite is available if searched out, and when mixed from bulk chemicals and packaged in your own containers is much more economical than buying actual Tannerite.