Originally Posted by NMOFT
I'm using 5.8 grains of bullseye. I've got lots of unique on hand, I'll check my reloading manuals for charge weights in .45 ACP. I just finished up a batch of .44 spl. with 7.5 gr unique and a 250 gr bullet. I find unique to be kind of dirty in a revolver but very accurate.
I have used Bullseye in several cartridges with cast bullets. There is a point somewhere just below 5 grains where it starts to lead. I can't really say why and it's kind of odd since I'm talking about small cases like 9mm and bigger ones like 45ACP. 5.8 may be fine in terms of a being a safe load pressure wise, but I think it is past the leading zone with bullets that aren't diamond hard.
Try something just short of max with Unique or maybe just 5.0 of Bullseye and see how it does. It might be easier than tinkering with alloys. Of course, there is nothing wrong with working on a better alloy, it's just that better alloys cost money and since you already have other powders, I find it cheaper and easier to adjust powder charges.