I've been using around 23 grains of H110 and a 240 Hornady xtp. I am going to try some hard gas checked bullets in it. I have had great luck with the H110 and was wondering how fast I could safely push this through my Henry Big Boy steel with the cast. I had tried 2400 with the xtp but the H110 gives way better groups. Not over max but the H100 does better the hotter it gets as far as grouping. I didn't get a chance to chronograph the xtp but I am figuring from my Loading manual around 1700 fps. That's just me guessing.