Processed and PRIMED .357 Magnum Pistol Brass Headstamps Are Mixed Fully Processed, Primed, and Ready To Load 100% Brass Casings 500 Casings Shop processed and primed .357 magnum range brass for reloading. Cleaned, processed, and primed with Ginex small pistol reloading primers for immediate use. Primed .357mag reloading casings are ideal for .357 Mag reloaders looking to save time without compromising quality. This 357 magnum primed brass is ready to be reloaded. Available in bulk quantities.