You could not have made a better choice. .54 is my favorite caliber. 90 grains of Pyrodex RS and a .530 roundball.. and there is not a deer, bear, moose, elk, nothing that can take a kill zone hit from that rifle.
I have always claimed the roundball, especially the .54 caliber is one of the most deadly projectiles made. At moderate to close range that ball is hard to beat. It's 232 grains of pure lead that hits, flattens and makes a huge hole coming out the other side. Many 1-48 twist Hawkens will shoot sabots as well. So if you want to try that route.. my Lyman Trade Rifle flintlock does a real good job.
The only roundball .54 I ever recovered from deer was I shot one deer at 80 yards with my .54 Renegade using 90 grains of Pyrodex RS. It went through him, dropping him in his tracks (high shoulder shot) and then hit a doe behind him. It broke her spine, dropping her, and lodged under the skin on the other side of the spine. I always get a pass through with the roundball. They just are a great projectile. Not fancy, easy to cast yourself, and cheap to shoot. But a great hunting projectile.