You wouldn't want to use "straight lead" in a .45 Colt, it should be alloyed, something like wheel weights, but not "hard cast." The 255 gr. flat nose bullet is a traditional load in .45 Colt. The Unique loads have always worked for me; I've tried others including Trail Boss.I don't want to use straight lead
I no longer cast bullets, but when I was doing it, I concentrated on the ones that were more expensive to buy. Like .45 Colt and .45-70. No sense wasting time on .32 revolver bullets when you could buy them by the hundreds for a low price.
If I wasn't a bullet caster, one I would buy: Hornady 45 Cal .454 255 gr FP Cowboy™ Item #12458. These are cold swaged, not cast. This is a traditional profile .45 Colt bullet, they use a mica lube on it that works well. The bearing surface of the bullet is knurled, the mica gets into the knurling and ensures good lubrication. I've used lots of these in .38 Special and .45 Colt. Today, they cost between $49 and $60 something per box of 200, if you can find them in stock.