Lloyd, I too have used 2400 in the 45-70, and had great results with a few loads. It's not that I've had any ignition problems (I never have), it is simply that at lower pressures in shorter barreled handguns, I get a lot of unburned powder kernels until I get up to what I believe is around 30,000 C.U.P. I didn't think I could come anywheres near that level in this thin barrel, maybe I'm wrong. At your suggestion I did try some after work today, but I guessed way too low on the charge, 14 grains with a 500 grainer. I didn't need to chronograph to tell it was off. Lots of unburned powder on first shot and a mild pop, cleaner and a bigger bang on #2, and back to dirty and a pop on #3. The group wasn't too super either. I need a full day to work with this powder, maybe it'll be great. I'll let you know ASAP. Thanks.