I had been working up some of Taffens 300 grain 44 mag loads using 10 grains of unique. This is considered to be a meek load for 44 mag. I used standard primers. The load shot great out of my Henry 44 mag. No recoil excellent accuracy. BUT, the casings all split in half right where the bullet was seat inside. Complete case separation into two rings. But the primers weren't flattened. I tried 6 rounds. All did this. Kinda odd right? I'm thinking of not crimping them and seeing if that fixes it or backing off to 9.5 grains. I did have complete powder burn.