An apparatus, comprising: a substrate configured into a casing, a propellant configured between a projectile positioned/configured within the casing and an end of the casing, the propellant configured to expand upon a firing event and project the projectile from the casing; and a coating comprising a conformal coating layer having a particulate boron nitride dispersed therein, wherein the coating is configured to cover at least one of the inner sidewall and the outer sidewall, such that at least one side of the substrate is covered by the coating.