CCI Muzzleloading Primers are built to provide the most reliable, consistent ignition possible in dry and humid conditions with reduced fouling. One of the benefits of using primers specifically designed for muzzleloading rifles is that they are milder than regular 209 shotshell primers meaning they do not force the powder charge forward helping to maintain consistent velocities and they help to minimize the formation of crud rings. These primers are not designed to be used in shotshells, they are designed for muzzleloading rifles only. Features Optimized for muzzleloadingReduces foulingFormulated to ignite in humid conditions