No experience here with the 24b or 28b light, short cartridge bore rifles, on any kind of game.

24b = .579"
28b = .550"

One of our members, a rifle builder from Wyoming named SZIHN, or a member from Canada, a man named Daryl, might be able to shed some light for you on the performance of roundball in these diameters from various charges of blackpowder in muzzle-loading rifles.

You need to define how much powder though.
As these rifles are all so unique, and there were different weights of rifle (and lengths of cartridge, lengths of barrel), and since this question seems to be an excursion of rhetorical nature, you need to fill in some of the blanks before you'll get solid answers regarding performance of projectiles scaled to the bore sizes you note and the relative nature of 'light' 'weak' etc

Again, running examples of these old rifles are extremely rare here in the 21st century.
You are likely to get good field report data, but you need to consider the 'on the ground' reality of how scarce these rifles you ask about are.

--Tinker