A plastic WW .410 hull, loaded with a bullet and full of black powder, will be considerably more powerful than same pressure loaded .45 Colt ctg.
I assume the case allowed is only the 2 1/2" case, not the 3", but that still should allow a really good BP charge. These one piece hulls are VERY easily cleaned afterwards, but then, so is brass.
The .410 Hull, loaded with bullet and BP, along with a roll crimp is the way to go. More aesthetic too.
Just checked a 2 1/2" WW AA .410 hull and it will hold 45gr. 3F GOEX and a 200gr. .45 bullet. That's 10gr.to 15gr. more than a modern .45 Colt case will hold.