Priming compounds are highly sensitive explosive that, when struck with the firing pin or hammer of a weapon, will explode violently and cause a fire to ignite the propellant. The explosive chemical is usually mixed with other chemicals which help in the production of flames, fuel to extend the duration and temperature of the flame, and glass that is ground to act as an abrasive for the initial ignition of the explosive. https://gunsvalley.com/product/209-primers/