357 Magnum HEI (High Energy Ignition) Incendiary ammunition is an ultra-sensitive .357 Magnum round engineered for maximum thermal performance, far exceeding standard incendiary options. Upon impact, it unleashes a brilliant, ultra-bright flash that is clearly visible across massive distances, day or night. Delivering a staggering 3,750°F momentary flame—nearly eight times hotter than the 451°F ignition point of paper—this round ensures immediate combustion upon contact. Formulated with a federally compliant mixture, it stands as the definitive choice when you absolutely, positively must guarantee ignition.