I commend you on your choice of a .24 gauge, for starters. I have found that the larger the bore, the harder it is to get a tight pattern at range. You will find smaller bore smoothies tend to string shot due to the small bore, that naturally starts the shot column out quite long. But it is much tighter from a smaller bore.
Don’t be afraid to try the patchless balls. Native Americans didn’t patch the round ball loads in their trade guns. The trick is velocity, big powder charges, and no patch, teamed with an undersized ball (about 20 to as much as 40 thousandths). These loads will shoot pretty flat, and straight, until the velocity bleeds off.
The other fringe benefit is if you get ahold of .58 Mini’s they shoot pretty well, and they are great for dangerous game, and big hard to kill game as well. Good luck.
Hungry Horse