Binary exploding targets typically consist of two separate components: an oxidizer and a fuel, neither of which is explosive on its own. A common formulation uses ammonium nitrate as the oxidizer and aluminum powder as the fuel. These components are mixed only at the point of use and require a high-velocity impact, generally from a centerfire rifle projectile of .223 caliber or larger, to initiate a reaction. The reaction produces a loud report and a visible cloud of dust, serving as a clear indicator of a successful shot.
The popularity of these targets stems from their utility in long-range shooting practice and firearm training. The immediate audible and visual feedback allows shooters to instantly assess their accuracy without needing to walk downrange or use spotting scopes. However, due to the energetic nature of the reaction, proper handling and safety precautions are paramount. Regulations regarding their use vary by jurisdiction and should be carefully researched and followed. Historically, similar formulations have been used in various industrial and mining applications.