Some real-world shooting conditions require more aggressive initiation than provided by standard primers. Large cases, cold weather, and certain propellants often require a hotter primer flame and a longer burn. CCI Magnum primers offer you that edge, plus you get all the attributes that make all CCI primers so great. Features:23 percent hotter flame than standard primersIncreased flame durationInitiator compound engineered to ignite ball/spherical propellantsImproved sensitivity for critical-need loadingLarge capacity casesHeavily-deterred propellantsAmbient firing temperatures below 20 deg F