I have used IMR 800-x in pistols and revolvers in the past for full loads.....
but it does not meter well and is pretty bulky, however it works great
in a 38 1 7/8 inch with a 125gr for a maximum loading.
Works for 12 Ga. steel loads also.
Just have a lot of Alliant to burn up before I need to grab the new IMR pistol powders.