I'll second what Paul B just said; there are plenty of powders out there that will give you the results you want without the need for fillers. In .45LC, I've been using Unique (7.5-8.0 grains) with great results -- accurate and easy to handle (plus a little smoke with cast bullets which looks good coming out of a ColtSAA
). I'm also looking into Hodgdon's Titegroup; I'm going to try some as soon as I can find it. Titegroup was designed to not be position sensitive so it will work well (ie..consistently) in large cases such as the .45LC and is a very clean burner (from what I've read).