Interesting question. I wonder if you'd be able to get enough powder into it to make it work well. The recipes I've seen -- and don't rush to your loading bench with this advice because I'm only paraphrasing from memory-- is that you use a few grains of smokeless followed by a gas check, followed by shot, followed by an inverted gas check and a roll crimp. Speer might make plastic shot cups for 45LC (I know they make them for 38, 44, and 45ACP.) Using the gas check method, I don't think you'd have enough room in the case for powder. Using the shot cup, you probably will because the cup extends beyond the case mouth.