Recently loaded some 7.62 x39 using IMR 4198 powder and Federal large rifle primers, 123 SP Berrys plated bullets. Shooting in a Ruger American Ranch rifle that has performed flawlessly thus far with factory ammo and my reloads. The last batch of reloads resulted in delayed detonation (hang fires). Has anyone experienced similar issues with IMR 4198 powder and Federal 210 primers? Wondering as this is the first episode of hang fires I have experienced. Shooting factory 7.62x39 ammo after the hang fires resulted in back to normal operation. I’m thinking there may be something amiss with the primers or the powder.