Nothing wrong with that. I love both cartridges and their ancestors and I think the .45ACP has a lot to offer in a single action. I've wanted one of the .45 convertibles for a long time but have put it off because I'd rather have an Old Model .357 converted.
I know you didn't just reference those .410 thingies!!!
I've found that 45 ACP actually makes a pretty darn practical field cartridge, and in a light SA, is quite fun. When I envisioned my "perfect" single action, it was in ACP. The new mid frame Flattops come pretty close right out of the box.
Throats got uniformed in this guy.
THE CHAIR IS AGAINST THE WALL.
The Tikka T3 in .308 Winchester is the Glock 19 of the rifle world.